The Quality of Life of Couple’s Affected by Multiple Sclerosis€¦  · Web viewThe author of the study defined independence as the ability to ‘pursue their goals and aspirations’

The Subjective Quality of Life of People

with MS and their Partners

Kylie King, B.Sc (Melbourne), P.Grad.Dip.Psych (Melbourne)

This thesis is submitted in partial fulfilment of the requirements for the

degree of Doctorate of Psychology (Health)

School of Psychology,

Faculty of Health and Behavioural Sciences,

Deakin University (Burwood)

Victoria, Australia

October 2001

DEAKIN UNIVERSITY

CANDIDATE DECLARATION

I certify that the thesis entitled:

“The Subjective Quality of Life of People with MS and their Partners”

submitted for the degree of Doctor of Psychology (Health) is the result of my own

research, except where otherwise acknowledged, and that this thesis in whole or in

part has not been accepted for an award, including a higher degree, to any other

university or institution.

Full Name: KYLIE ELIZABETH KING

Signed………………………………………………

Date…………………………………………………

TABLE OF CONTENTS

Abstract......................................................................................................................... 2

Acknowledgements....................................................................................................... 3

List of Contents............................................................................................................. 4

List of Tables................................................................................................................ 5

List of Figures............................................................................................................... 5

List of Appendices........................................................................................................ 5

i

ABSTRACT

This thesis explored the validity of a model, based on previous research, to

explain the way in which psychological factors interact to maintain subjective

quality of life in the adaptive range of 50-100%SM (Scale Maximum) for

individuals in normal life circumstances. Subjective quality of life was proposed

to be maintained by psychological factors including personality, positive

cognitive biases of self-esteem, primary control and optimism and perceived

social support. Furthermore, it was proposed that secondary control mediates

between positive cognitive biases and subjective quality of life. The study

explored the subjective quality of life, and associated psychological factors, of

people with Multiple Sclerosis (MS) a chronic debilitating illness of the central

nervous system, partners of people with MS, and a comparison control group.

The first study utilised a technique called ‘photovoice’ to explore the factors that

influence the subjective quality of life of people with MS and the ways they cope

with everyday difficulties. Nine people with MS were provided with disposal

cameras and were asked to take photographs of things that either positively or

negatively effected their quality of life. The photographs were then used to

stimulate discussion in quantitative interviews. Participants reported varied

influences on their quality of life and ways of coping with everyday difficulties.

Items were added to the questionnaires of the second study based on this

information.

The second study involved 65 people with MS, 37 partners of people with MS,

and 93 comparison controls who completed a self-report questionnaire designed

to measure the variables of the model cited above. People with MS reported a

lower subjective quality of life than both partners and controls. The model

predicted a substantial proportion of the variance in the subjective quality of life

of the controls (45%), people with MS (59%) and partners of people with MS

(58%). The findings are discussed in relation to previous research and to

potential interventions aimed at improving subjective quality of life.

ACKNOWLEDGEMENTS

There are so many people to acknowledge for their contribution not only to this

thesis but also to my personal growth and happiness over the last three years.

I thank the MS Society of Victoria and their members for their commitment to

this project. I thank the people with MS and their partners who took part in this

research, and the others that didn’t take part but provided me with support and

encouragement along the way. People who took time out to let me know that they

thought what I was doing was valuable and worthwhile.

I thank my supervisor Prof. Bob Cummins for his dedication to this thesis. His

assistance with conceptual and technical matters was invaluable. His enthusiasm

for research and confidence in my abilities when I needed them most will not be

forgotten. I thank also all the other staff at Deakin University who supported me

with their patience, wisdom, and encouragement. I especially Kate Moore who

looked after us Healthies all the way.

I thank my fellow students especially Maria, Tina, and Olivia for their complete

understanding, support and tolerance even though they were struggling with their

own difficulties. I am sure I have made friends that will last a lifetime.

I thank my other friends, family, and my partner Travis for never once letting me

believe that I could not make it. I thank them also for their financial support that

made this all possible, for cheering me up when I was stressed and sad, for

understanding when I couldn’t return their unwavering support, and for reminding

me that there are some things more important than a thesis. I only hope that I can

one-day repay the support you all provided.

iii

LIST OF CONTENTS

LIST OF TABLES

LIST OF FIGURES

LIST OF APPENDICES

CHAPTER 1INTRODUCTION TO THE THESIS

Multiple Sclerosis (MS) is a chronic, degenerative illness of the central nervous

system. The course of the illness is largely unpredictable, and its potential

symptoms are wide ranging (Ko Ko, 1999). People with MS often experience

downward fluctuations in physical and mental ability. There are few effective

treatments for MS, and there is little knowledge regarding its aetiology (MS

International Federation, 2001). The symptoms of the illness, its unpredictable

course, and the limited availability of treatments, often negatively effect

psychosocial functioning and well-being. It is therefore likely that people with

MS will benefit from research that focuses on enabling them to live full and

satisfying lives within the unique constraints of their condition. The following

thesis has this focus.

This thesis is premised on a model, based on previous research, that describes

how people evaluate the quality of their lives. A large body of research has

attempted to identify the factors that enable people to live full and satisfying lives.

This thesis reviews this research and integrates common findings in the

development of a model. The resulting model is then tested using people with

MS, their partners and a control comparison group. An outline of the chapters of

the thesis now follows.

Outline of the Thesis

In the next chapter, the thesis discusses the symptoms, prevalence, treatment,

psychosocial impact of MS, and the rationale for the focus on this illness. It

provides the context for the research within the unique characteristics of the

illness, which is potentially stressful and challenging to an individual’s

satisfaction with life.

1

In the third chapter, the definition and measurement of subjective quality of life is

discussed. This is necessary as the area is laden with definitions, which are often

used interchangeably, yet are theoretically distinct. This chapter provides a

conceptual framework for the thesis.

Chapter 4 describes the impact of life circumstances and subjective factors on

quality of life. The consistency of life quality evaluations across individuals is

discussed. This provides evidence for the limited influence of objective life

conditions.

Chapter 5 describes the psychological factors that are held to be associated with

subjective quality of life, namely: personality, positive cognitive biases,

secondary control, and social support. The interactions between these factors are

examined.

Chapter 6 summarises the research reviewed in earlier chapters. A model is

proposed to explain the process by which identified psychological factors interact

to maintain subjective quality of life. This model is based on previous research.

Chapter 7 presents the first of two linked studies designed to test the model. This

is a qualitative study, comprising interviews with people with MS. It seeks to

identify the factors contributing to evaluations of life quality. The findings of this

study were used to ensure that the material for the second study, a self-report

questionnaire, was both valid and sensitive to people with MS. The study resulted

in some modifications to the material, including the addition of new items and the

re-wording of other items.

Chapter 8 presents the second study. This study explores the proposed model

using a larger group of people with MS, partners of people with MS and a control

comparison group. Hypotheses based on the model are tested via a self-report

questionnaire. The study reveals differences between the three groups, and

support for the interactions between variables proposed by the model.

Chapter 9 reconciles the findings of the thesis with the research reviewed in the

first five chapters. This chapter explores the implications of the findings for

people with MS, partners of people with MS, people unaffected by chronic

illness, and interventions aimed at these groups. Limitations of the current

research and avenues for future research are discussed, and conclusions regarding

the thesis are drawn

CHAPTER 2MULTIPLE SCLEROSIS

MS is one of the most common diseases of the central nervous system in adults

and affects over two and a half million people worldwide (MS Society Australia,

2000). The symptoms of the disease are widespread and unpredictable, such that

individuals are often faced with changes in physical and mental ability.

Prevalence

MS affects three women for every two men (MS Society Australia, 2000). Onset

is most common in early adulthood, with a peak between the ages of twenty and

forty-five. Thus, the disease tends to occur at the same time that individuals are

beginning to establish families, occupational careers and financial security.

Consequently, MS can exert powerful influences on psychosocial functioning.

Disease Symptoms and Course

People with MS will usually experience a variety of neurological impairments

including muscle spasticity, with or without muscular weakness. They may also

experience impairments in cognition, vision, balance, bladder and sexual function

(Ko Ko, 1999). However, while MS is a degenerative disease, it does not appear

to appreciably shorten life span (Rao, Huber & Bernstein, 1992). MS may result

in crippling physical disability requiring full time care. However, essential bodily

functions remain intact.

It is not possible to predict the course of the disease at the time of diagnosis on the

basis of clinical presentation or immunological findings (Thompson, Colville,

Ketelaer & Paty, 1994). It is, however, possible to recognise broad categories of

the disease and to roughly classify people according to the differing temporal

course of their illness. Thus, 50 to 60% of people with MS fall into the category

of Relapsing-Remitting MS, characterised by recurrent attacks of neurological

dysfunction followed by periods of complete or incomplete remission. 10 to 20%

of patients fall into either Primary Progressive MS, marked by relentless decline

in neurological function and disability, or Secondary Progressive MS where a

relapsing-remitting course has converted to a progressive course. In the third

category of Benign MS, there may be a long period between the recognised onset

of the disease and development of significant disability. 20 to 30% of people with

MS have a benign disease course (Rao, Huber & Burnstein., 1992).

Aetiology

The symptoms of MS are caused by scarring of the myelin sheath that insulates

nerve fibres of the central nervous system (MS Society Australia, 2000).

However, very little is known about the aetiology of this scarring. The aetiology

may involve either a genetic predisposition or an immune reaction to a virus (MS

Society Australia, 2000).

Treatment

Currently there is no cure for MS. Facets of the disease have recognised

treatments that are effective for some people. For example, steroids are

administered in acute exacerbations as they reduce the duration and allow a return

to normal function to occur more rapidly (MS International Federation, 2001).

There are also drugs that have some effect on the frequency and severity of

exacerbations; including Interferon Beta and Copolymer 1. These are

administered by subcutaneous self-injection on a daily basis (MS International

Federation, 2001).

Psychosocial Impact

The stressors experienced by people with MS are likely to be wide ranging and

diverse due to the unpredictable nature of symptomatology and disease course,

and the limited treatment options. These stressors may comprise dealing with

physical limitations, the psychological strain of maintaining a positive self-

concept, adjusting to role changes, and confronting one’s own mortality (Larsen,

1990).

Partners of People with MS

Partners of people with MS are also likely to experience wide-ranging stressors

related to the illness. For example, they may become the sole income earner for

their family, they may experience sadness and disappointment related to their

partner's difficulties, and may grieve for the future they had planned that is no

longer attainable. Also, many are involved in their partner’s care (Pakenham,

1998; Schofield, Herrman, Block, Howe & Singh, 1997). Even when other

people are available to provide care, partners almost exclusively carry the burden

of care in the home (Carton, Loos, Pacolet, Versieck & Vlietinck, 2000). This

may require lifestyle adjustments and added pressures. Indeed, while being a

partner or a carer is stressful, people who are both partners and carers to people

with MS are likely to more distressed than people who fill only one of these roles

(Aronson, 1997).

Part of the stress experienced by people with MS and their partners may be due to

impact of MS on social functioning. For example, symptoms of MS may restrict

lifestyles resulting in changes to social networks (Bartels DesRosier, Cantanzaro

& Piller, 1992). The social activities of both people with MS and their partners

outside the relationship may be constrained, especially if the person with MS is

dependent on their partner for care due to motor difficulties, cognitive impairment

or other MS symptoms. Partners may be less able to take part in satisfying

activities over a number of life domains due to physical limitations. For example,

partners may need to reduce or cease employment, or they may have to give up a

leisure pursuit due to the demands of caregiving.

Intimate Relationships

Some of the stress experienced by partners may also be explained by the effect of

MS on intimate relationships. MS may impact intimate relationships through its

effect on personality and sexual dysfunction. Personality change is common in

MS (McIntosh-Michaelis, Roberts, Wilkinson, Diamond, McLelllan, Martin &

Spackman, 1991) and may result in altered interpersonal functioning. This may

cause distress for the partner who is faced with caring for someone who may be

markedly different from the person they once knew. Consistent with this,

research indicates that partners generally experience more distress as a result of

the psychological rather than physical incapacity of their partner with MS (Miller,

Berrios & Politynska, 1996).

Sexual dysfunction is also common (Dupont, 1996). Difficulties may include

lack of orgasm, impotence, disturbances of sensation, and lack of libido that are

more common in males (Burnfield & Burnfield, 1982; Dupont, 1996). These

difficulties have implications for partners' sexual functioning. In evidence of this,

partners also show high levels of sexual dysfunction, especially in the areas of

avoidance and infrequency of sex (Dupont, 1996). This is especially problematic

as sexual functioning is positively associated with the quality of intimate

relationships (McCabe, McDonald, Deeks, Vowels & Cobain, 1996). Thus,

people with MS and their partners are likely to experience relational difficulties.

Given the potential strains placed on the relationships of people with MS, it is not

surprising that relationship dissatisfaction is common. Between a quarter and a

third of people with MS and their partners report some dissatisfaction with their

relationship, and partners are more dissatisfied than people with MS (Dupont,

1996). This dissatisfaction has been linked to symptoms of MS, and marriage

breakdown is positively associated with increased physical disability (Hammond,

McLeod, Macaskill & English, 1996). However, other research indicates that the

strain of having a partner with MS is more related to the subjective experience of

caregiving than objective illness characteristics (O’Brien, Wineman, & Nealon,

1995).

While MS negatively effects many relationships, not every intimate relationship is

unsuccessful or unhappy. Indeed, some people report improvement in their

relationships. McCabe et al (1996) found that about one third of people with MS

reported closer relationships, and about one third indicated no change. Thus, it

may be that while MS can negatively change interpersonal relationships, it can

also result in improvements in other relationships, and can have a negligible

impact on others. Further research is needed to explore the impact of MS on the

functioning of intimate relationships, however this is beyond the scope of this

thesis.

Summary

MS is a relatively common disease of the central nervous system with wide-

ranging and unpredictable symptoms and disease course. The disease potentially

provides a complex set of stressors for both the person with MS and their partner.

These can potentially result in relationship dissatisfaction, and reduced subjective

quality of life. The following chapters explore the influence of both objective life

conditions such as illness, and subjective factors such as personality and coping,

on quality of life. It will be demonstrated that the way in which people interpret

and cope with life events influences how people feel about their lives more than

objective life conditions, such as illness. Thus, research based on subjective

factors is likely to be beneficial to people with MS and their partners who are

forced to maintain their quality of life in the face of potentially stressful life

circumstances.

CHAPTER 3SUBJECTIVE WELL-BEING, LIFE SATISFACTION AND SUBJECTIVE

QUALITY OF LIFE

How people feel about themselves and their lives has been the focus of much

research. It is an area laden with definitions. Subjective well-being, life

satisfaction, and subjective quality of life are some of the many terms used by

researchers to describe how people feel about themselves and their lives.

Colloquially, these terms are often used interchangeably. Theoretically they have

distinct meanings yet opinions continue to differ on the use of this terminology.

For the purpose of this thesis the following taxonomy will be adopted.

Subjective Well-Being

Subjective well-being is the most global term used to describe how people feel

about their lives. It includes people’s emotional responses, satisfaction with life

domains, and global judgement of life quality (Diener, Suh, Lucas & Smith,

1999). Thus, subjective well-being comprises measures of cognition (satisfaction)

and affect (positive affect) (Cummins, 2000). The cognitive component of

subjective well-being can be described in two ways: life satisfaction and

subjective quality of life.

Life Satisfaction

Life satisfaction refers to a single judgement concerning satisfaction with one’s

life based on the difference between one’s circumstances and an internally

imposed standard (Cummins & Nistico, in press). This is measured by asking

respondents a single question: ‘how do you feel about your life as a whole?’

(Andrews & Whitey, 1976). This provides a global measure of how people feel

about their lives.

Subjective Quality of Life

Subjective quality of life is defined as an evaluation of life satisfaction across a

number of life domains. This differs from objective quality of life, which is an

evaluation of a life in relation to externally imposed objective standards such as

where people live, their income or occupation. Evaluations of subjective quality

of life are therefore determined by an interaction of personal values, life

conditions, and life satisfaction (Felce & Perry, 1995). Such an approach

considers subjective quality of life to be composed of discrete life domains.

There is no agreement as to the number of domains that comprise subjective

quality of life. Cummins (1999) defines quality of life as the aggregate of the

seven domains of material well-being, health, productivity, intimacy, safety,

community and emotional well-being. However, additional life domains, such as

spiritual well-being, leisure and usefulness may also be important to people living

under particular circumstances. A life domain of ‘independence’ may be

especially relevant to people with disabilities. A recent study of the aspirations of

over four hundred and forty-four people with disabilities in Victoria found that

independence was a major aspiration of people with disabilities (Johnson, 2000).

The author of the study defined independence as the ability to ‘pursue their goals

and aspirations’ (p31) and concluded that ‘for people with disabilities, if quality

of life were to be boiled down to one word, it would be independence’ (p. 16).

However, such research does not elucidate the importance of independence to

people with disability relative to people without disability, nor does it establish

whether this domain of life is independent of the other life domains.

The measurement of discrete domains of quality of life has the potential to

provide much more information about individual evaluations than the global

approach. For example, the relative importance of each domain varies between

individuals, and some domains have a consistently stronger influence on

subjective quality of life than other domains (e.g. Mellor, Cummins & Loquet,

1999). Thus, some domains account for a larger proportion of subjective quality

of life than others. The domain of 'intimacy', regarding relationships with family

and friends, is such a domain. This domain is consistently judged both the most

important and the one from which most satisfaction is derived (Mellor, Cummins

& Loquet, 1999).

Information regarding different life domains is most useful for improving

individuals’ subjective quality of life. Cummins (1999) proposes that deficits in

subjective quality of life incurred by disability or disease may be offset by the

positive experiences within other life domains. For example, improvements in the

domain of intimate relationships can counter dissatisfaction with other life

domains (Mellor, Cummins & Loquet, in press). This has implications for people

with MS and their partners who often report dissatisfaction with intimate

relationships and suggests that interventions aimed at improving these

relationships will likely be more beneficial to subjective quality of life than

interventions aimed at other domains.

Summary

Three terms used to describe how people feel about their lives were discussed:

subjective well-being, life satisfaction and subjective quality of life. Each term

describes a different aspect and measurement of the construct. This thesis is

concerned with subjective quality of life as it potentially provides the most

information regarding different facets of satisfaction with life and subsequently

avenues for improving how people feel about their lives. The next two chapters

explore both the objective and subjective influences on subjective quality of life.

CHAPTER 4THE INFLUENCE OF OBJECTIVE LIFE CONDITIONS ON

SUBJECTIVE QUALITY OF LIFE

Life circumstances, or objective life conditions, have a limited influence on

subjective quality of life. Objective factors account for only approximately 15%

of the variance in subjective well-being (Argyle, in press). This is evidenced by

the consistency of life satisfaction evaluations between people with very different

objective life conditions. For example, Cummins (1997b) found that college

students, adolescents attending high school and people with intellectual

disabilities reported no differences in life satisfaction despite substantial

differences in their objective life quality. Life satisfaction evaluations are so

consistent that a ‘gold standard’ has been developed. Cummins (1995) compared

sixteen western general population studies on life satisfaction. Among these

studies, fourteen different measures of life satisfaction were employed. To enable

comparison of the studies, each study’s life satisfaction scores were converted to a

percentage of the maximum score obtainable on the scale (SM). There was

remarkably little variation in mean sample life satisfaction scores between the

studies despite little commonality in their methodologies. Following from this, it

was proposed that the life satisfaction gold standard be considered as 75.0 +/-

2.5%SM. A later review by the same author of two hundred and six articles

concerning the topic of life satisfaction confirmed a world range in life

satisfaction of 60 to 80%SM and approximated that the adaptive range was

between 50 and 100%SM (Cummins, 1998b).

The consistency of life evaluations across different life circumstances suggests a

psychological mechanism that attempts to maintain subjective well-being within a

set range. The presence of a such a ‘set point’ for subjective well-being was first

proposed by Headey and Wearing (1989) and is evidenced by the limited long-

term influence of negative events on subjective quality of life. For most people,

negative events tend to depress subjective quality of life only in the short term,

such that people tend to recover to their set point some time later (Cummins, in

press).

Adaptation level theory (Helson, 1964) partially explains the consistency of

subjective quality of life evaluations across markedly different life circumstances.

This theory proposes that subjective well-being is maintained through processes

of habituation and contrast. People compare current levels of stimulation to the

level of stimulation to which they have been previously accustomed. This results

in a shift of adaptation level. Extreme good fortune results in an upward shift of

adaptation level. Consequently, many of the ordinary life pleasures seem more

neutral. Highly negative events, on the other hand, cause a downward shift in

adaptation level such that previously neutral events now seem pleasurable

(Brickman, Coates & Janoff-Bulman, 1978). However, this mechanism can be

defeated by chronic life conditions that impose a burden that is too strong to allow

for adaptation (Cummins, 2000). As discussed previously, MS can induce a wide

range of stressors. Thus, MS potentially imposes a burden that is too strong to

allow for adaptation and can result in decreased subjective quality of life.

The Influence of Multiple Sclerosis on Subjective Quality of Life

MS is a life condition that can potentially negatively effect subjective quality of

life. People with MS commonly report a lower life satisfaction than both people

without illness (Canadian Burden of Illness Study Group, 1998; Gulick, 1997;

Nortvedt, Riise, Myhr & Nyland, 1999). They also report a lower satisfaction

with life than people with other chronic illnesses such as inflammatory bowel

disease and rheumatoid arthritis (Rudick et al, 1992), and epilepsy and diabetes

(Hermann et al, 1996). It has been suggested that some factors of MS uniquely

contribute to lowered quality of life. These include the unpredictability of

attacks, fear of progression and neuro-behavioural symptoms (Ko Ko, 1999).

There is some debate regarding the influence of the physical symptoms of MS on

subjective quality of life. While, those living a longer time with MS are likely to

have increased levels of disability (Barnwell & Kavanagh, 1997), adjustment to

MS is not necessarily related to a longer disease duration (Barnwell & Kavanagh,

1997), nor disability severity (Aronson, 1997; Barnwell & Kavanagh, 1997;

Burnfield & Burnfield, 1982). However, quality of life may be influenced by the

course of the illness. For example, decreased quality of life is associated with a

more progressive disease course (Pfennings et al, 1999). The previously

discussed habituation and contrast process that act to maintain subjective well-

being may explain these seemingly inconsistent findings. While, individuals may

be able to adjust to disability from other disease courses through habituation and

contrast, this process may be defeated by a progressive disease course that is

characterised by an unpredictable and unrelenting deterioration in physical ability.

Individuals may be unable to restore normal levels of subjective well-being before

further deterioration is experienced.

It is likely that partners of people with MS also have lowered subjective quality of

life due to the complex nature of the stressors they can experience. Consistent

with this, carers of people with MS experience compromised life satisfaction and

psychological distress which is lower, but positively correlated with their care

receiver’s psychological distress (Pakenham, Stewart & Rogers, 1997).

Caregivers of people with other illness also experience decreased subjective

quality of life. This has been found to be three standard deviations below the base

score of the normative range (Cummins, 2001). It was concluded from this

review of research on the quality of life of carers that ‘caregivers of severely

disabled people are at extreme risk of being highly stressed, clinically depressed

and with a subjective quality of life that is way below normal’ (Cummins, 2001, p

24). However, as discussed earlier, partners may be even more likely than carers

to be negatively affected by MS. This may be due to the physical symptoms of

MS, the way in these symptoms constrain one’s lifestyle, and the psychological

toll of caregiving and living with the illness.

Assessing Quality of Life in MS

Few studies have explored the process whereby MS exerts its influence on

subjective quality of life. Instead, previous research on subjective quality of life

has generally utilised subjective quality of life assessments as outcome measures,

to assess treatment effectiveness (Vickery, Hays, Harooni, Myers & Ellison, et al,

1995). Illness specific measures, such as the Multiple Sclerosis Quality of Life

Instrument (Vickery et al, 1995) and the Multiple Sclerosis Quality of Life

Inventory (Fisher et al, 1999), have been developed with this aim in mind. These

are self-report instruments that ask a series of questions to assess the impact of

MS on physical health, emotional well-being, social functioning, cognitive

functioning, sexual functioning, health distress, and overall quality of life.

More general ‘health related quality of life measures’ have also been developed.

These measures comprise physical, mental and social health measures. Health

related quality of life measures that are regularly used with people with MS

include the Medical Outcome Short Study Form-36 (Ware, Snow, Kosinski &

Gandek, 1993), the Disability and Impact Profile (Laman & Lankhorst, 1994).

These two kind of measures assess health status and the impact of illness on

lifestyles and emotional well-being. These instruments specific to people with

illness are not useful when comparing people with MS to other groups of people.

Also, the Disability Impact Profile and the Multiple Sclerosis Quality of Life

Inventory combine objective and subjective evaluations of factors thought to

influence quality of life, including measures of MS based on physical symptoms.

This is problematic because, as previously discussed, objective circumstances and

subjective experiences differentially effect quality of life. The current research

utilises a self-report measure of the impact of MS such that only subjective factors

are included in the thesis. The effects of objective and subjective factors are

therefore differentiated. Also, the thesis utilises a generic measure, rather than an

illness specific measure, of subjective quality of life so that different groups of

people with and without illness can be compared.

Summary

Objective life conditions normally have only a limited influence on subjective

quality of life. Evaluations of subjective quality of life are remarkably consistent

across varying life circumstances. The existence of a mechanism that keeps

subjective quality of life at a set point has been proposed. This mechanism may

involve processes of habituation and contrast. However, this mechanism can be

defeated by chronic life conditions that impose a burden that is too strong to allow

for adaptation. MS potentially imposes such a large burden both for people with

MS and their partners. Research is needed that clearly differentiates between

objective and subjective influences, and delineates the psychological factors and

processes that influence the subjective quality of life of people with MS. Such

research will assist interventions aimed at improving the quality of life of people

with MS by highlighting potential targets for effective intervention.

The following chapter explores the various psychological factors that have been

associated with subjective quality of life. These are then combined into a model

that describes the mechanism by which subjective quality of life is maintained in

the adaptive range of 50 to 100%SM proposed by Cummins (1995).

CHAPTER 5THE INFLUENCE OF PSYCHOLOGICAL FACTORS ON SUBJECTIVE

QUALITY OF LIFE

Various psychological factors have been associated with subjective quality of life.

This chapter reviews the current state of research regarding the influence of these

factors. The variables most consistently related to subjective quality of life are

personality, positive cognitive biases in self-esteem, primary control and

optimism, secondary control and perceived social support. These will now be

described in more detail in relation to previous research and Multiple Sclerosis. A

model is then proposed to explain the process whereby these factors interact to

maintain subjective quality of life.

Personality

Personality can be defined as a complex system of internal constructs (Smith &

Vetter, 1998) that have a strong genetic link. Tellegen et al. (1998) found, in

their study of monozygotic and dizygotic twins reared apart and together, that on

average about 50% of measured personality diversity could be attributed to

genetic diversity. They concluded that environmental influences generally play a

very modest role in the determination of many personality traits.

The personality traits of extraversion and neuroticism have received the most

attention in relation to subjective well-being. While, extraversion traits contribute

to positive enjoyment without reducing the unpleasantness of adverse

circumstances, neuroticism traits predispose one to suffer more acutely from

misfortunes, without diminishing positive experiences (Costa & McCrae, 1980).

These stable traits predispose people to experience moderately stable levels of

favourable and adverse life events and moderately stable levels of subjective well-

being (Headey & Wearing, 1989). Specifically, decreased neuroticism and

increased extraversion are consistently associated with increased subjective

quality of life for both people with illness (Gurizerath, Connelly, Albert, &

Knebel, 2001; Hyland, Bot, Singh, & Kenyan, 1994; Yamaoka, et al,1998) and

people without illness (Francis & Bolger, 1997; McCrae & Costa, 1991;

Pastuovic, Kolesaric, & Krizmanic, 1995).

Extraversion and neuroticism have been strongly linked to trait positive and trait

negative affect (Fogarty et al, 1999), which also predict subjective well-being.

Indeed, Watson and Clark (1984) argue that measures of negative affect,

neuroticism and other apparently diverse personality scales are in fact measures of

the same stable and pervasive trait. Trait positive and negative affect can be

thought of as pervasive affective states that influence responses to situations

(Clark & Watson, 1991). Trait affect reflects differences in negative mood and

self concept (Watson & Pennebaker, 1989). Individuals high in negative affect

are more likely to experience distress and dissatisfaction at all times and across

situations, even in the absence of overt stress (Watson & Clark, 1984). Trait

positive affect reflects differences in energy levels, excitement and enthusiasm

(Watson & Pennebaker, 1989). Positive affect may buffer the individual from

harmful effects of stress by influencing coping strategies, so that individuals high

in positive affect are less affected by stressors (Fogarty et al, 1999).

Personality and Multiple Sclerosis

The association between subjective well-being and personality may be

confounded for people with MS by emotional disturbance and cognitive

impairment. Emotional disorders are more common in MS than in conditions that

produce roughly equivalent degrees of physical disability, such as rheumatoid

arthritis, spinal cord injury and muscular dystrophy (Rao, Huber & Burnstein,

1992). Common emotional disturbances include euphoria and depression. These

emotional changes seem to have a specific temporal distribution. The earlier

stages of the disease are associated with depression that is likely to reflect the

emotional toll of living with MS (Gilchrist & Creed, 1994). The later stages of

the disease however are associated with euphoria which likely results from

increasing cognitive disturbance in association with widespread cerebral

involvement (Rao, Huber & Burnstein, 1992).

Many people with MS also experience cognitive impairment. McIntosh-

Michaelis et al (1991) found cognitive impairment in 46% of one hundred and

forty-seven people with MS, memory impairment in 34% and failure on tests of

frontal lobe function in 33%. Cognitive impairment may occur very early in the

course of the disease (Rao, Huber & Burnstein 1992). It is likely that these

changes affect the subjective quality of life of people with MS, and those close to

them, in a number of ways. Changes in personality characteristics may change

the way in which individuals perceive and cope with stressors, and may cause

frustration and depression. This may result in new conflicts in interpersonal

relationships.

These changes in emotional and cognitive functioning may then alter the

relationship between personality and subjective quality of life for people with MS

in comparison with other people. Euphoria and cognitive impairment may also be

associated with a loss of personal insight and judgement that may confound

reports of subjective well-being and quality of life for the person with MS.

Summary

The personality traits of extraversion and neuroticism have been consistently

associated with subjective quality of life. These are closely linked to positive and

negative affect. It is likely that personality influences subjective quality of life in

two ways. Personality can influence the perception of stressors and can effect

coping efforts. The influence of personality on subjective quality of life is likely

to be compromised for people with MS who experience emotional disturbance

and cognitive impairment that may result in personality changes.

Positive Cognitive Biases

Positive cognitive biases have been associated with subjective quality of life.

Specifically, research suggests that self-esteem, control, and optimism contribute

to the maintenance of satisfaction with life. Taylor and Brown (1988) claim that

most individuals possess a very positive view of the self and that these positive

views are associated with a variety of positive effects such as positive mood,

social bonding, higher motivation, greater persistence, and ultimately greater

success. It has been proposed that satisfaction of the need for self-esteem,

primary control and optimism is dependent upon the presence of positive

cognitions regarding these aspects of the self (Cummins & Nistico, in press).

The basis of these self-enhancing positive cognitive biases probably lies in the use

of social comparison. Individuals tend to overestimate their own good qualities

relative to their assessment of others’ qualities (Brown, 1986). Cummins and

Nistico (2001) claim that encountering failure may maintain the optimal upper

boundary of positive cognitive bias. However, excessive failure may serve to

lower subjective quality of life. This thesis proposes that a coping mechanism

mediates between positive cognitive biases and subjective quality of life. The

three positive cognitive biases are now addressed in turn.

Self Esteem

Self-esteem is defined as ‘liking and respect for oneself’ (Rosenberg, 1979 p45).

Whilst all people display a pervasive tendency to cast themselves in more positive

and less negative terms than they portray other people, persons with high self-

esteem are most likely to offer a more flattering portrayal of their self (Brown,

1986). Taylor and Brown (1998, 1994) claim that such self-aggrandizing views

are linked to psychological well-being. Cummins and Nistico (in press) reviewed

six studies concerning self-esteem and life satisfaction and found that self-esteem

was strongly correlated with life satisfaction. This may be due to a direct effect

on well-being, or indirectly through coping efforts. In evidence of this, self-

esteem has been linked with primary control strategies in people with MS

(O’Brien, 1993) and with the use of effective coping strategies in people without

illness (Schutz, 1998).

Control

Control has been consistently associated with subjective quality of life in two

ways: as a generalised belief in personal competence, or as a positive cognitive

bias, and as a coping mechanism once a stressful encounter has taken place. A

definition of stress is integral to these functions of control. Stress is defined here

as ‘a relationship between the person and the environment that is appraised by the

person as taxing or exceeding his or her resources and as endangering his or her

well-being’ (Folkman, 1984, p. 840). These two functions of control are now

discussed in more detail

Control as a generalised belief in personal competence can be thought of as a

belief concerning the extent to which he or she can control outcomes of

importance. In a specific stressful encounter, control can also be thought of as a

situational appraisal of the possibilities for control. Existing as a belief, control

does not need to be exercised for it to be effective and control does not need to be

real, just perceived, for it to influence the aversiveness of a stressful encounter

(Thompson, 1981). Thus, generalised beliefs of control affect whether situations

are perceived as stressful. Situations will be perceived as less stressful if the

individual believes they are controllable. Those with a stronger sense of personal

control, mastery, or self-efficacy cope better with chronic illness. They are more

likely to make desired behaviour changes and have better psychological well-

being (Thompson et al, 1998).

Control as a coping mechanism can be viewed as a cognitive mediator of a

stressful transaction and its adaptational outcome (Folkman, 1984). Thus, once a

situation is assessed as a stressor, coping efforts mediate the effect of this stressor

on subjective quality of life. Coping can be defined as “constantly changing

cognitive and behavioural efforts to manage specific external and/or internal

demands that are appraised as taxing or exceeding the resources of the person”

(Lazarus & Folkman, 1984, p. 141). Previous research has identified many

different ways that individuals cope with stressful situations. Various typologies

have been proposed to describe the functioning of control. These include:

primary and secondary control, problem and emotion focused coping, and

behavioural, cognitive, informational and retrospective control. These are now

described.

Primary and Secondary Control

The primary and secondary typology of control mirrors the two functions of

control. Primary control can be generally defined as a belief that one can

influence existing realities (Wiesz et al., 1984) and is akin to the aforementioned

positive cognitive bias of control. An example of this is the belief that one will

loose weight by exercising. Secondary control, on the other hand, can be defined

as accepting or adjusting to one’s situation, such as when one is having trouble

loosing weight. Secondary control involves cognitive strategies such as goal

disengagement and social comparison. For example, telling oneself that loosing

weight is not important, or by comparing oneself to heavier individuals.

Other researchers (Heckhausen & Schulz, 1995) have defined primary and

secondary control based principally on their targets. They define Primary control

as focussing on the external world, and secondary control as focussing on the self.

These two definitions of primary and secondary control are similar. However,

this thesis adopts the first definition of primary and secondary control proposed

by Wiesz et al. (1984). This definition focuses on the function rather than the

target of control. Other typologies of control have been attempted along similar

conceptual lines.

Problem and Emotion Focussed Coping

Folkman and Lazarus (1980) define control as a coping mechanism with two

major functions: management of the problem that is causing the distress

(problem-focused) and regulation of emotion or distress (emotion-focused).

Whilst this typology is similar to that of primary and secondary control, similarly

to Wiesz et al.’s (1984) primary and secondary control definition, it is focused on

the target rather than the function of control and arguably neglects generalised

beliefs in personal competence. This function, as previously outlined, can also act

to mediate potentially stressful transactions.

Behavioural, Cognitive, Informational, and Retrospective Control

Thompson (1981) proposed another typology of control. This is a fourfold

typology of control consisting of: behavioural control, cognitive control,

information, and retrospective control. Behavioural control is defined as a belief

that one has a behavioural response available to affect the aversiveness of an

event. Cognitive control is defined as the belief that one has a cognitive strategy

available that can affect the aversiveness of an event. Informational control refers

to a communication delivered to a person who is the potential recipient of an

aversive event. Retrospective control refers to beliefs about the causes of the

event. This typology is very similar to the primary and secondary typology, with

the addition of information and retrospective control. These additions are

arguably superfluous. Informational control can be viewed as a factor external to

the individual’s coping, and as a component of the stressor, which may or may

not translate into beliefs in personal control and coping efforts. Retrospective

control is better conceptualised as a type of primary control. For example, by

comparing oneself to heavier individuals after failing to loose weight, one can re-

interpret failure as success in order to gain retrospective control. Thus,

retrospective control can be viewed as beliefs in personal control (primary

control) after coping efforts (secondary control) have been utilised.

In summary, the typology of primary and secondary control is adopted to

conceptualise the function of control. This conceptualisation is the only one of

the three discussed that incorporates the two functions of control. These are a

coping mechanism once a stressful encounter has taken place, and a generalised

belief in personal competence. The primary and secondary control typology is

also the only one to focus exclusively on the action of control rather than the

target. Considerable research has explored the relative influence of primary and

secondary control on subjective quality of life.

The Adaptive Outcomes of Primary and Secondary Control

The potential for primary and secondary control and the relative influence of each

on subjective quality of life depends on the particular person and the specific type

of encounter. As such, there may be no universally good or bad coping process,

however there may be some that are more often better or worse than others

(Lazarus, 1993). The influence of primary and secondary control on subjective

quality of life in different life circumstances is now discussed. For the purposes

of this discussion, the term ‘adaptive’ is used to describe a function that has a

positive influence on subjective quality of life.

The Uncontrollability Model (Koller & Kaplan, 1978) claims that perceptions of

uncontrollability and decreased motivation for control can fuel one another in a

downward spiral, such that in some situations people abandon the quest for

control. However, this is unusual. Control is so valued that the quest for it is

rarely abandoned. Individuals are instead likely to shift from one method of

control to another (Rothbaum, Weisz & Snyderl, 1982) and strive to establish a

balance between primary control and secondary control (Lazarus, 1981; Weisz,

Rothbaum & Blackburn, 1984). However, sudden and substantial losses in

primary control are likely to be particularly challenging in that they do not allow

individuals time to adapt and compensate through secondary control before

significant loss occurs. Over time, crises such as these can be overcome as

control is re-established and elaborated (Heckhausen & Schulz, 1995).

The influence of primary and secondary control on subjective quality of life is

effected by the potential for utilisation. Throughout the course of life, potential

for primary control and secondary control undergoes major changes. The

potential for primary control may be constrained by health factors, social

institutions, and mental capacity (Heckhausen & Schulz, 1995). Also, an

individual’s background and past experience may determine the relative emphasis

placed on each type of control (Rothbaum et al., 1982). For example, Western

societies view primary control as preferable to the use of secondary control

strategies. However, collectivist cultures, such as Asian cultures, stress close

alignment with others and discourages attempts to make realities fit one’s own

wishes (Weisz et al., 1984). Thus, the influence of primary and secondary control

on subjective quality of life is not absolute, and depends on other factors such as

the desirability or availability of control.

Two major models have been proposed to explain the adaptive outcomes of

primary and secondary control, and the process of re-establishing control in

response to a crisis. These are the Discrimination Model (Folkman, 1984;

Thompson et al, 1998) and the Primacy/Back-up Model (Heckhausen & Schulz,

1995). Recent research also suggests a third possibility related to the balance

between primary and secondary control.

The Discrimination Model (Folkman, 1984; Thompson et al, 1998) proposes that

perceptions of primary control are adaptive when the situation is controllable, and

acceptance (or secondary control) is more adaptive when the situation is not.

Thus, secondary control acts to compensate for losses in primary control to

protect emotional well-being. In contrast, the Primacy/Back-Up Model

(Heckhausen & Schulz. 1995) claims that primary control is the more adaptive

strategy regardless of the controllability of the situation. The function of

secondary control in this model is to compensate for low primary control and help

bolster feelings of overall control in all types of situations. It is unclear whether

the Primacy/Back-Up Model or Discrimination Model best describes the adaptive

outcome of primary and secondary control.

According to the Primacy/Back-Up Model, Thompson et al (1998) claimed that

primary control is associated with good psychological outcomes even in very low

control circumstances. Consistent with this, reductions in primary control and

increased use of secondary control have been found to have negative

consequences. Nütterland and Ahlström (1999) found, in a study of individuals

with Muscular Dystrophy and Post-polio Syndrome, that problem-focused

(primary control) strategies were not used frequently and that this was commonly

associated with feelings of helplessness and hopelessness. Aikens, Fischer,

Namey et al (1997) also found that a high rate of escape avoidance coping, a type

of secondary control, was possibly predictive of future distress in people with MS

with mild physical disability.

However, in contrast with the Primacy/Back-Up Model, perceptions of primary

control may be maladaptive in situations where primary control is impossible or

very unlikely. Also, recent research found that secondary control’s role in

positive adjustment comprises more than just acting to compensate for low

primary control (Heeps, 2000). A number of studies support this assertion. For

example, Affleck, Tennen, Pfeiffer and Fifeld (1987) found an association

between disease severity and the adaptiveness of perceptions of control in

Rheumatoid Arthritis patients. Perceiving control over symptoms was unrelated

to mood in patients with mild symptoms, but was significantly associated with

positive mood in patients with moderate to severe symptoms. In contrast,

perceiving primary control over the course of the disease was marginally

associated with positive mood in patients with mild disease, but significantly

associated with negative mood in patients with severe disease. Thus, as the

disease worsened, perceiving control over presumably uncontrollable factors

(disease course) was emotionally maladaptive. Burish et al (1984) similarly found

that an external locus of control, reflecting relinquished perceptions of primary

control, was adaptive for a sample of cancer patients. Eitel, Hatchett, Friend,

Griffin and Wadhwa (1995) also found a negative relationship between control

over treatment options, and emotional well-being with increases in end-stage renal

disease severity. Chipperfield, Perry, and Menec (1999) found that secondary

control strategies became increasingly adaptive with age and declining health, and

presumably decreased opportunities for primary control. These findings highlight

that, in some situations, individuals prefer control in hands of people able to

minimize future danger, such as health professionals. An external orientation,

reflecting acceptance of a loss of primary control, may reduce distress associated

with a lack of control and increase the likelihood that patients will follow the

advice of medical staff regarding treatment. Eitel et al. (1995) proposed that only

when an illness becomes severe or poses a serious threat to the individual do

perceptions of control over treatment negatively effect psychological adjustment.

These findings are consistent with Folkman’s (1984) assertion that when

individuals prefer not to have control, increased choice or participation may

heighten stress (Folkman, 1984). They are also consistent with the

Discrimination Model that claims that primary control beliefs may become a

disadvantage when they have a low probability of success. Thus, it may be that

high beliefs in primary control are adaptive as long as they remain untested

(Thompson et al, 1988).

So far, these models have described the adaptive value of absolute levels of

primary and secondary control. However, recent research suggests that the

availability of strategies, as well as the use of strategies, is related to adaptive

functioning. Optimally adaptive functioning is reported by people unaffected by

chronic illness who have a repertoire of control strategies involving relatively

high levels of both primary and secondary control (Heeps, 2000). People with a

control imbalance, that is average or above average levels of one control process

but below average of the other, report lower levels of positive psychological

adjustment compared to people with average or above average levels of both

(Heeps, 2000). Taken together with the research supporting the Discrimination

Model, this recent research suggests that the availability of high levels of primary

and secondary control strategies to an individual and the use of these strategies in

accordance with the Discrimination Model are related to optimally adaptive

functioning.

The research discussed so far has focused on the adaptive functioning of

individual use of primary and secondary control. However, couples tend to react

to disease as a unit, such that their use of coping strategies (emotion or problem

focused) is matched and their well-being is highly correlated (Pakenham, Dadds,

& Terry, 1995). Individual coping efforts may effect both their partner’s coping

efforts and their subjective quality of life. The limited research on this topic

suggests that the similarity of coping between partners and the couple’s average

levels of coping are positively associated with well-being (Pakenham, 1998;

Revenson, 1994). Thus, the relationship between partners’ use of primary and

secondary control may also be related to well-being.

Summary

Control has been associated with subjective quality of life in two ways: as a

positive cognitive bias of personal competence and as a coping mechanism once a

stressful encounter has taken place. The terms ‘primary’ and ‘secondary’ control

are used to describe these two processes. Research suggests that for individuals,

the availability of high levels of primary and secondary control strategies and a

preference for primary control unless the situation is uncontrollable are related to

optimally adaptive functioning. For people with partners, similarity in the use of

primary and secondary control with their partner and a high level of couple

primary and secondary control use may also be related to optimally adaptive

functioning.

Optimism

Positive cognitive biases of optimism refer to a set of positive beliefs regarding

oneself in the future. Robinson and Ryff (1999) claim that perceptions of future

well-being, or optimism, are particularly subject to self-enhancement biases. Also

they claim that self-deception is greatest under conditions of information

uncertainty and high motivation. Thus, relatively concrete information about the

future will serve to minimize such enhancement. An absence of relatively

concrete information about the future provides an ideal opportunity for

envisioning the best possibilities for one’s self. The way individuals view their

future and present may also be motivated by their ‘possible selves’. These selves

‘are the ideal selves that we would much like to become. They are also the selves

we could become and the selves we are afraid of becoming’ (Markus & Nurius,

1986, p. 954). Possible selves are important because they function as incentives

for future behaviour and provide an evaluative and interpretative context for the

current view of self.

Research has documented diverse benefits of optimism. Optimism has been

negatively related to depression in MS (Fournier, de Ridder, & Bensing, 1999). It

has been related to adjustment and well-being in people with coronary heart

disease (Scheier et al., 1989), and other people unaffected by chronic illness

(Aspinwall &Taylor, 1992). It has been proposed that optimism exerts its

influence directly on well-being (Aspinwall & Taylor, 1992) and through coping

efforts. In relation to this, optimism has most commonly been associated with a

higher use of primary control strategies (Aspinwall & Taylor, 1992; Friedman et

al., 1992; Scheier et al, 1989; Strutton & Lumpkin, 1992). However, for people

with MS, emotion-focused coping has been found to mediate the impact of

optimism on depression (Fournier, de Ridder, & Bensing, 1999). Although these

findings appear to conflict, they are consistent with the Discrimination model of

control (Folkman, 1984; Thompson et al, 1998), which claims that perceptions of

primary control are adaptive when the situation is controllable and that secondary

control is more adaptive when the situation is not controllable. Thus, optimists

adopt adaptive coping strategies dependent on the controllability of the situation.

Consistent with this, Scheier, Weintraub, and Carver (1986) found that optimists

tend to adopt strategies that are more effective when coping with stress.

The Adaptive Outcomes of Positive Cognitive Biases

While research discussed above has demonstrated the benefits of positive

cognitive biases, Colvin and Block (1994) argue that there is insufficient evidence

that unrealistic optimism is positively related to mental health. They claim that

cognitive distortions about oneself and one’s social surroundings can not result in

adaptive behaviour over long periods of time in a world that provides feedback or

reacts on the individual.

Baumeister (1989) suggested a compromise between these seemingly

incommensurable views in his ‘Optimal Margin Hypothesis’. He proposed that

optimal psychological functioning is associated with a slight to moderate degree

of distortion in one’s perception of the self and the world, such that there is an

optimal range for positively biased cognitions. Provided that cognitive biases are

maintained within some homeostatic range which prohibits the emergence of

delusions (defined as being beyond the normal adaptive range and severely

incongruent with reality), they constitute an adaptive mechanism for the

maintenance of subjective quality of life. It is possible therefore, that such

positively biased cognitions constitute an adaptive mechanism that creates and

maintains mean population life satisfaction in the range of 50-100%SM.

In summary, positive cognitive biases in self-esteem, primary control and

optimism have been proposed to constitute an adaptive mechanism for the

maintenance of subjective quality of life. Furthermore, the current research

proposes that secondary control strategies act to maintain positive cognitive biases

in an adaptive range in the face of failure. When faced with stressful situations,

secondary control strategies act to accommodate the information so that subjective

quality of life is not decreased. These may include social comparison as proposed

by Brown (1986). The influence of positive cognitive biases on subjective quality

of life may be compromised for people with MS in a number of ways.

Cognitive Biases and Multiple Sclerosis

The maintenance of an optimal margin of cognitive distortion may be problematic

for people with MS due to unpredictable changes in physical and mental ability.

The individual may be frequently presented with feedback inconsistent with their

positively biased cognitions. As their ability levels fluctuate so too does their

optimal margin of cognitive bias. This necessitates constant restructuring of

cognitive biases. For example, a person with MS may believe themselves to be a

good mother. However, this belief may be challenged by fluctuations in their

physical abilities, which restricts them from carrying out tasks they believe a good

mother should carry out. While failure experiences may maintain the upper

boundary of positive cognitive biases (Cummins & Nistico, in press), frequent

feedback from the external environment that is inconsistent with positively biased

cognitions lowers the optimal upper boundary of cognitive biases more than is

adaptive for people with MS. This may result in a reduction of positively biased

cognitive distortion that has a negative impact on subjective quality of life.

Self-Esteem and MS

Consistent with the hypothesised effect of failure experiences on positive

cognitive biases, people with MS have a self-concept that is more negative than

people without chronic illness that tends to remain stable after an initial

adjustment period of approximately ten years (Brooks & Matson, 1982). It seems

that the secondary control strategies maintaining positive cognitive biases in the

face of failure are defeated following diagnosis of MS, but that over time positive

cognitive biases are re-established. However, it is also likely that positive

cognitive biases are never fully restored to levels comparable to those without

chronic illness (Brooks & Matson, 1982).

Primary Control and MS

As discussed, positive biases of primary control are not always adaptive. Indeed,

the Discrimination Model of control (Folkman, 1984; Thompson, et al, 1998)

proposes that for people in uncontrollable situations, secondary control may be

more adaptive than primary control. However, there is limited research regarding

the adaptive function of cognitive biases of primary control specifically regarding

people with MS. Pakenham (1999) found that the use of problem-focused coping

(primary control) was associated with better adjustment to multiple sclerosis than

the use of emotion-focused coping (secondary control). Other research that has

looked at control in relation to MS exacerbation found that people with MS

tended to favour emotion-focused coping techniques whilst in periods of illness

exacerbation, and problem-solving or the use of social support in periods of

remission (Warren, Warren & Cockerill, 1991). Thus, the limited research

suggests that people with MS use primary and secondary control in the way

described by the Discrimination Model and that this is adaptive. They use

primary control in times when the situation is controllable and secondary control

when the situation is less controllable.

However, the ability of people with MS to maintain primary control and mediate

their stress through secondary control may be compromised due to the

unpredictable nature of their illness. Individuals may be faced with variations in

the adaptiveness of primary and secondary control due to their fluctuating ability

to control life situations. For example, behavioural efforts to seek control may be

limited by disability and reliance on others that varies between illness remission

and exacerbation. Generalised beliefs in personal control may also be

compromised by the unpredictable nature of MS, rendering the individual with

little information as to the future course of their illness, to the difficulties that they

may face, or to their ability (physically and emotionally) to deal with these

difficulties. Consistent with this, an association between uncertainty regarding

the future and psychosocial adjustment has been found in people with another

chronic condition, diabetes (Landis, 1996). It therefore seems likely that people

with MS may be at risk of using primary and secondary control in less than

optimal ways, which may result in lowered subjective quality of life.

Optimism and MS

Whilst positive cognitive biases regarding the present are likely to be diminished,

especially in people who have been newly diagnosed, the research previously

outlined suggests that positive cognitive biases regarding the future (optimism)

are likely to be large in people with MS who have little concrete information

about the future. As discussed, self-deception is greatest under conditions of

information uncertainty and high motivation. MS is an extremely unpredictable

condition. As such, MS is likely to provide circumstances of information

uncertainty. People with MS are likely to be highly motivated to avoid a future

possible self that may be severely disabled and crippled by MS. Also, the

individual may be unsatisfied with their present self. Thus, MS is also likely to

provide circumstance of high motivation. These factors taken together suggest

that positive cognitive biases regarding the future are likely to be larger in people

with MS than other people. Consistent with this is Fournier, de Ridder &

Bensing’s (1999) finding of significant unrealistic optimism with regards to

negative events in a sample of people with MS. Unfortunately, these findings

were not compared to people without chronic illness. As individuals without

chronic illness also exhibit positive cognitive biases regarding the future (Brown,

1986), one cannot conclude based on this information whether people with MS

have greater biases of optimism than other people. This thesis will explore this

issue by comparing the magnitude of optimistic bias between people with MS and

people unaffected by chronic illness.

Summary

Positive cognitive biases in self-esteem, primary control and optimism have been

proposed to maintain subjective quality of life within the range of 50 to 100%

SM, provided they are within the threshold for the ‘optimal’ range of cognitive

bias. However, positive cognitive biases may affect the subjective quality of life

of people with MS differently than other people without chronic illness. It is

likely that people with MS experience more failure experiences that serve to

decrease the positivity of their cognitive biases and may experience difficulty

mediating their stress through secondary control. In contrast, people with MS are

likely to demonstrate greater bias in optimism than other people due to the

unpredictable nature of MS.

Perceived Social Support

Social support has also been positively associated with subjective quality of life

(Abbey, Abramis & Caplan, 1985; Holahan et al, 1996; Revenson, Schiaffino &

Gibofsky, 1991; Schaefer, Coyne & Lazarus, 1981). Several considerations are

necessary when assessing social support. Firstly, perceptions of availability of

social support, rather than the use of social support, are related to well-being.

Thus, a measure of the perceived availability and value of social support is a more

sensitive indicator of its effects than objective measures. For example,

Cunningham McNett (1987) found that perceived availability of social support

was positively related to coping effectiveness in wheel-chair-bound individuals.

Schaefer et al. (1981) similarly found that perceived social support was more

strongly associated with well-being than objective measures of social networks in

a general population sample. They claimed that when objective measures of

social network size are used to indicate the benefits of social support, two

questionable assumptions are made. One is that any benefits are directly

proportional to the size of the network. The second assumption is that having a

relationship is equivalent to getting support.

The second consideration necessary when assessing social support is that social

support can be characterised as either positive or problematic. Positive support is

characterised by social interactions that provide affect, affirmation, or aid.

Problematic support is defined as instances of social interaction that are perceived

as non-supportive, even though the provider’s actions may have been well

intended. Both positive and problematic support appeared to make independent

contributions to psychological well-being (Holahan et al, 1996; Revenson et al,

1991). In summary, when assessing the effect of social support on subjective

quality of life, it is necessary to use a subjective measure that is sensitive to both

potential positive and problematic aspects of social support.

There has been considerable debate regarding the association between stress,

perceived social support and subjective quality of life. Two explanations have

been proposed. The buffering hypothesis proposes that support buffers people

from stressful events. The second hypothesis proposes a direct effect: that social

support has a beneficial effect irrespective of whether people are under stress

(Cohen & Wills, 1985). The evidence for the hypotheses is now discussed.

Consistent with the stress-buffering hypothesis, social support has been shown to

have an impact on positive well-being for people under stress. Social support

plays an important role in coping and psychosocial adjustment in individuals and

families with MS (Weinert, 1988). Social support also has a substantial impact on

positive well-being for people with arthritis (Germano, 1996), and coronary heart

disease (Holahan et al, 1996). Social support enhances recovery, increases

adherence to treatment recommendations and promotes psychological adjustment

(Revenson et al, 1991). Abbey et al. (1985) also found support for the stress-

buffering role of social support for normal people experiencing different levels of

stress. However, consistent with the proposed direct effect, social support also

has a beneficial effect for people not under stress. For example, Schaefer et al.

(1981) found a direct positive association between perceived social support and

emotional well-being in their general population sample, but found no support for

the proposed stress-buffering effect of social support.

Cohen and Wills (1985) claimed that this phenomenon is explained by the

presence of a threshold for social support. This threshold may change in response

to stressful life circumstances, such that the phenomenon of social support as a

buffer against life stressors simply reflects a heightened need, or threshold, for

social support. When people are under stress, people may require more social

support or feel the absence of social support more acutely. It is likely therefore

that people with MS require more social support than others in order to maintain

their subjective quality of life, especially during times of illness exacerbation.

In addition to exerting a direct effect on subjective quality of life, perceived social

support may also influence the perception of stressors. As discussed earlier, stress

is defined as an environment that is appraised as taxing or exceeding resources

and endangering well-being (Folkman, 1984). Social support can influence the

perception of a stressor by providing the individual with resources to deal with

life circumstances. With higher levels of resources, individuals with high levels

of perceived social support are likely to view fewer situations as exceeding their

resources than someone with low levels of perceived social support.

Perceived social support may also exert its effect on subjective quality of life

indirectly by effecting the use of secondary control strategies. Individuals with

high levels of perceived social support may utilise different secondary control

strategies than those low in perceived social support. Consistent with this

supposition, Holahan et al (1996) found that social resources were significantly

related to the use of coping strategies that were also significantly associated with

well-being in people with coronary heart disease.

In summary, perceived social support has been found to have a positive influence

on subjective quality of life. Perceived social support can be classified as two

types: problematic and positive. These differently influence subjective quality of

life. Thus, measures of social support need to be subjective and sensitive to the

potential problematic and positive effects of social support. It is likely that there

is a minimum threshold for perceived social support. When people are under

stress this threshold rises such that they have a heightened need for social support.

As well as exerting a direct effect on subjective quality of life, it is proposed that

perceived social support may also influence the perception of stressors. A

discussion of the ways in which MS may effect social support follows.

Social Support and Multiple Sclerosis

While it is likely that people with MS have heightened social support needs,

social support may nevertheless be compromised for people with MS. Decreased

social support has been inversely associated with the length of illness (O’Brien,

1993), and increasing disability for people with MS (Stenager, Knudsen, &

Jensen, 1991). A decrease in perceived social support coupled with a heightened

need for social support will likely result in reduced subjective quality of life for

people with MS. Consistent with these propositions, Aronson (1997) found that

interference by MS with social activities is strongly associated with decreased

subjective quality of life. Perceptions of social support and social activity may

decrease for people with MS and their partners for a number of reasons. For

example, physical disability may restrict both the person with MS and their

partner’s ability to maintain social interaction, and their potential increased

reliance on others can alter relationships.

Many people with MS are unemployed. Between 50% and 80% of people with

MS are unemployed within ten years of disease onset (Ko Ko, 1999). Hammond

et al (1996) examined over two thousand people with MS in Australia, overall

50% of men and 27% of women reported being unemployed and they found

lower rates of participation in the paid workforce in more disabled patients.

People with MS are also less likely to be employed than people with other chronic

conditions such as inflammatory bowel disease and rheumatoid arthritis (Rudick,

Clough, Gragg & Farmer, 1992). Unemployment can negatively affect social

support and, in turn, subjective quality of life. Consistent with this,

unemployment has been significantly associated with social support (O’Brien,

1993) and with the reported quality of life of people with MS (Aronson, 1997;

Gulick, 1997).

Partners of people with MS may also have compromised social support, as their

activities may also become restricted. Consistent with this, chronic illness

research of married couples shows that they spend more time with each other in

the home and less time in network relationships and activities outside the home

(Bartels DesRosier, Cantanzaro & Piller, 1992). Also, while intimate

relationships positively impact on subjective quality of life for people without

illness (Diener et al, 1999), the link between intimate relationships and subjective

quality of life is not as clear for people with chronic disability. Intimate

relationships have been positively associated with subjective quality of life of

people with MS (Gulick, 1997). However, in a study of wheel-chair-bound

individuals, Cunningham McNett (1987) found that non-married subjects coped

more effectively than married subjects.

Summary

Perceived social support has been positively associated with subjective quality of

life. It is likely that there is a minimum threshold for perceived social support,

which increases in time of stress. Thus, this threshold is likely to be raised in

people with MS, such that they feel the absence of perceived social support more

acutely than other people. However, this increased need for social support is

likely coupled with decreased opportunities for social support through

unemployment and physical limitations. This is likely to have a negative impact

on their subjective quality of life.

Chapter Summary

The limited influence of objective life conditions and the consistency of life

satisfaction evaluations suggest that subjective quality of life is held at a set point

by a psychological mechanism. This chapter has so far reviewed and analysed the

current state of literature in regards to the psychological factors associated with

subjective quality of life and their relation to MS. The factors discussed were

personality, positive cognitive biases, social support and secondary control. The

following conclusions regarding these factors were reached.

The personality traits of extraversion and neuroticism are associated with

subjective quality of life. These traits may influence subjective quality of life in

two ways. Personality can influence the perception of a stressor and can act to

mediate the negative impact of a stressor on subjective quality of life through

coping efforts. This influence of personality on subjective quality of life is likely

to be compromised for people with MS who experience emotional disturbance

and cognitive impairment that may result in changes in personality.

Positive cognitive biases in control, optimism, and self-esteem have been

proposed to maintain subjective quality of life within the range of 50 to 100%SM,

provided they are within the threshold for the optimal range of cognitive bias.

The biases are maintained in this range by failure experiences and secondary

control. The size of these positive biases may be different for people with MS

than for people without chronic illness. This is based on the assumption that

people with MS likely experience more failure experiences that serve to decrease

the positivity of cognitive biases of self-esteem and primary control, and previous

research that suggests the unpredictable nature of MS may result in increased

biases of optimism.

Secondary control is proposed to mediate between positive cognitive biases and

subjective quality of life. Secondary control acts as a coping mechanism once a

stressful encounter has taken place and maintains the positivity of cognitive

biases. However, the adaptive outcome of primary control and secondary control

varies according to the controllability of life situations. The availability of high

levels of primary and secondary control strategies to an individual, and a

preference for primary control unless the situation is uncontrollable, are related to

optimally adaptive functioning. The use of primary and secondary control in this

optimally adaptive way may be difficult for people with MS who face

unpredictable changes in the adaptive outcome of primary and secondary control

due to their fluctuating disease course.

Perceived social support has been found to have a positive influence on subjective

quality of life. Perceived social support can be conceived as two types:

problematic and positive. These differently influence subjective quality of life. It

is likely that there is a minimum threshold for perceived social support. When

people are under stress, this threshold rises such that they have a heightened need

for social support. Thus, the minimum threshold for perceived social support is

likely to be raised in people with MS, such that they feel the absence of perceived

social support more acutely than other people. This is likely to have a negative

impact on their subjective quality of life.

While much previous research has explained the various associations between

psychological factors and subjective quality of life, less research has attempted to

delineate the process whereby these factors influence subjective quality of life.

This chapter has so far identified some of the factors that may be involved and

suggested how MS may effect these. The next section of this chapter combines

the identified psychological factors into a model proposed to explain the process

whereby the factors interact to maintain subjective quality of life in an adaptive

range across various life circumstances.

A Model for the Maintenance of Subjective Quality of Life

The literature review has identified some psychological factors involved in the

maintenance of subjective quality of life. It has been proposed that Helson’s

(1964) Adaptation Level theory may partially explain this consistency in

subjective quality of life evaluations. This theory proposes that subjective well-

being is maintained through a process of habituation and contrast. The literature

review revealed some other ways that psychological variables may be involved in

this process. Cummins and Cahill (in press) proposed a model to explain the

influence of personality and positive cognitive biases on subjective quality of life.

This model is presented in Figure 5. 1

Figure 5.1

Cummin and Cahill’s (in press) homeostatic model for subjective quality of life.

This model describes a system that combines a primary genetic capacity

(personality) with a secondary buffering system (positive cognitive biases).

Neuroticism and extraversion together provide an affective balance that produces

the mid point of the set-range for subjective quality of life, which on average is

75% SM. Positive cognitive biases constitute a regulatory system that integrates

affect, from personality, with cognitions regarding the external world (Cummins

& Cahill, in press).

Based on the research thus far discussed, this thesis adds two factors to this

model: perceived social support and secondary control. While Cummins & Cahill

(in press) acknowledge the role of these factors in maintaining positive cognitive

biases and subsequently subjective quality of life, they have not explicitly

included them in their model. This thesis asserts that these two factors play a

vital, and predictable role, in the maintenance of subjective quality of life. Thus,

Subjective Qualityof Life

Positive Cognitive Biases

Self-EsteemOptimism

Primary Control

ExtraversionNeuroticism

FIRST ORDERDETERMINANTS:Personality

SECOND ORDERDETERMINANTS:Internal Buffers

Environmental Factors

this thesis proposes an expanded model for the maintenance of subjective quality

based on Cummins and Cahill’s model and other previous research. This model is

shown in Figure 5.2.

Figure 5.2

Proposed model for subjective quality of life

In addition to Cummins and Cahill’s (in press) postulated links between

personality, positive cognitive biases and subjective quality of life, this thesis

proposes that secondary control mediates between positive cognitive biases and

subjective quality of life. Once a situation is viewed as stressful or otherwise

unfavourable it challenges positive cognitive biases. Secondary control acts to

accommodate stressful experiences through the process of habituation and

contrast proposed by Helson (1964), thus, maintaining subjective quality of life.

Thus, a positive evaluation of the self and subjective quality of life is maintained.

SecondaryControl

Subjective Qualityof Life

Perceived Social Support

ExtraversionNeuroticism

FIRST ORDERDETERMINANTS:Personality

SECOND ORDERDETERMINANTS:Internal Buffers

THIRD ORDERMEDIATING DETERMINANT

Positive Cognitive Biases

Self-EsteemOptimism

Primary Control

Environmental Factors

The adaptive functioning of primary and secondary control is integral to the

model. The availability of high levels of primary and secondary control strategies

to an individual and the use of primary control when the situation is controllable

and secondary control when the situation is not controllable are related to

optimally adaptive functioning (Folkman, 1984; Heeps, 2000; Thompson et al,

1998).

This thesis additionally proposes that perceived social support exerts a strong and

predictable influence on subjective quality of life. This is based on research that

has consistently demonstrated a positive association between social support and

subjective quality of life (Holahan et al, 1996; Revenson et al, 1991; Schaefer et

al., 1981). Furthermore, it is proposed, based also on previous research, that

perceived social support is subject to a threshold effect. This threshold changes in

response to stressful life circumstances, such that there is a heightened need for

social support. When people are under stress, they may require more social

support or feel the absence of social support more acutely (Cohen & Wills, 1985).

These two additions to Cummins and Cahill’s (2001) model will be tested in this

thesis in relation to people with MS, their partners and a group of comparison

controls. The potential ways that variables of the proposed model may be

compromised for people with MS have been discussed and are now summarised.

Positive cognitive biases are likely to be different for people with MS compared

to other people. Positive cognitive biases of self-esteem and primary control are

likely to be smaller for people with MS than other people as these people are

more likely to experience failures that maintain the upper boundary of positive

cognitive biases. However, positive cognitive biases of optimism are likely to be

larger for people with MS as MS provides the context of information uncertainty,

and high motivation that combine to produce greater biases in optimism.

Personality may be compromised in people with MS as they are likely to

experience personality change due to cognitive impairment and emotional

disturbance. Social support is also likely to be compromised in people with MS

as they are restricted in social interactions by the physical symptoms of MS.

Despite the potential differences between groups of people regarding the variables

of the model, this thesis hypothesises that the model is valid for all people across

different life circumstances, including people with MS. However, the variables of

the model may differently contribute to subjective quality of life depending on

life circumstances.

The generalisation of the model across different types of people in different life

circumstances differs from previous research that has focussed on specific groups

of people. For example, O’Brien et al (1995), and Stuifbergen, Seraphine, and

Roberts (2000) both proposed models to explain the process whereby

psychological variables influence subjective quality of life for people affected by

MS. While these models provide information that is relevant to people with MS,

research based on these models is not comparable to people without illness. This

limits the utility of the model. This thesis postulates that the processes involved

in maintaining subjective quality of life are the same for all people. Therefore,

models designed for use with all people are both valid and necessary to enable

comparisons between different types of people.

CHAPTER 6THE CURRENT THESIS

This thesis is concerned with the psychological factors and processes that

influence how people with MS and their partners evaluate their lives. Subjective

quality of life is adopted to define and measure this construct. Subjective quality

of life is defined as an evaluation of life satisfaction across a number of life

domains. Measurement of discrete domains of quality of life has the potential to

provide greater information about individual evaluations than the global approach

to quality of life evaluations.

A number of psychological variables were discussed in the previous chapters in

regard to their influence on subjective quality of life. Previous research has

hypothesised links between some of these variables and subjective quality of life.

This thesis hypothesises some new links. These links are combined into a model

proposed to explain the psychological maintenance of subjective quality of life for

people across different life circumstances. The relationships between the

variables are discussed in more detail in the introduction to the second study in

the eighth chapter. It is likely that the variables of the model interact differently

to maintain subjective quality of life for people with MS and their partners as the

variables of the model are likely to be compromised in a number of ways for these

people. This thesis will investigate how the psychological variables of the model

interact and influence subjective quality of life, and whether this differs between

people with MS, their partners, and people without chronic illness.

These questions are explored through two linked studies. The second study

investigates the variables of the model in people with MS, partners of people with

MS, and controls through a self-administered questionnaire. This study is

presented in chapter eight. While the utility of the subscales of the questionnaire

has been established for other populations, they have not been used previously

with a population with MS. A preliminary study was therefore required to ensure

that these questionnaires were relevant to this population. Study One, presented

in the next chapter, seeks to gain information to ensure that the proposed

questionnaires for the larger study are valid and useful. The general aims and

hypotheses of the thesis are now discussed.

Aims

The general aim of the thesis is to provide a greater understanding of the

psychological factors that influence the subjective quality of life of people with

MS and their partners, and to compare this to those unaffected by MS or other

major medical conditions. This will serve to enhance interventions aimed at

improving the subjective quality of life of these people. The thesis also aims to

promote further research into the quality of life of people with MS and their

partners, through the provision of a level of understanding from which other

research can build.

General Hypotheses

The general hypotheses for the thesis based on the proposed model for the

maintenance of subjective quality of life are as follows:

1. The variables of the model predict the subjective quality of life of

people with MS, their partners, and control. Specifically, subjective

quality of life is predicted by personality, positive cognitive biases,

and perceived social support. Secondary control mediates between

positive cognitive biases and subjective quality of life.

2. The variables of the model interact differently between the three

groups.

3. People with MS are subject to substantial stress from MS, thus their

subjective quality of life is lower than that of their partner, which is

in turn lower than controls who experience no systematic stressor.

Additional, specific hypotheses regarding interactions between the variables of the

model and differences between the three groups are discussed prior to the second

study in the eighth chapter.