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Pergamon hr. J. Nurs. Stud., Vol. 33, No. 3, pp. 259-270, 1996

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Effects of Orem-based nursing intervention on nutritional self-care of myocardial infarction patients

ARLENE E. AISH, Ph.D., R.N. School of Nursing, Queen’s University, Kingston, Ontario, Canada K7L 3N6

MARJORIE ISENBERG, D.N.Sc., R.N. Graduate School, College of Nursing, Wayne State University, Detroit, Michigan, U.S.A.

Abstract-The purpose of the study was to investigate the effect of nursing care based on Orem’s nursing theory on nutritional self-care of myocardial infarction patients. Self-efficacy was explored as a disposition which may motivate behavioral change. One hundred and four subjects were randomly assigned to treatment or control groups. The nursing intervention, which took place during the first 6 weeks following hospital discharge, was effective in supporting healthy low-fat eating behavior. Nursing care influenced patients’ self-care agency but lacked impact on self-efficacy for healthy eating. Copyright 0 1996 Elsevier Science Ltd.

Self-care of myocardial infarction patients

It is important for nurses to be able to clearly demonstrate the effectiveness of their contribution to patient care and to be able to identify what it is about a particular nursing approach that makes it effective. Utilization of a conceptual model of nursing can guide strategies for planning care and contribute to explanations of why the care produces desired patient outcomes.

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260 A. E. AISH and M. ISENBERG

The purpose of this study was to investigate the effect of a nursing intervention based on Orem’s (1985, 199 1) theory of nursing on the nutritional self-care of myocardial infarction (MI) patients. The theory of self-efficacy was explored as a motivating factor. MI patients are advised to follow a heart healthy diet with reduced fat and increased fiber intake in order to reduce the risk of recurrence, or of health complications, but many patients find incorporation of these dietary behaviors difficult (Neville, 1990). Nutritional self-care for MI patients involves initiating or maintaining heart healthy dietary patterns. Nursing care was designed to help MI patients increase their capability related to this aspect of their self- care following hospital discharge.

Conceptual framework

Orem’s (1985, 1991) self-care deficit theory of nursing conceptualizes self-care as the personal care that people require each day. The theory states that human beings have self-care agency (SCA) which is the capability for self-care. However, health-related limi- tations may interfere. Nursing is directed towards fostering and supporting the patient’s SCA because the patient’s level of SCA is expected to predict the quality and quantity of self-care. Orem posited eight universal self-care requisites which are required to maintain human structure and function. One of these, the need for food, is the focus of this study.

Orem’s theory provides guidelines for designing nursing care in specific situations. Guide- lines for motivating behavioral change are less evident, so the psychological theory of self- efficacy was included. Self-efficacy (Bandura, 1977, 1986) is a person’s belief in one’s own personal ability to exercise a specific behavior and to be strongly motivated to practice and to persist in this behavior. In this study, self-efficacy for the specific behavior of healthy eating was considered. It was expected that if nursing intervention was effective in assisting patients to become more capable of eating a heart healthy diet, then patients would become more confident in this ability and would be more motivated to practice and persist in healthy eating behavior because of their increased self-efficacy. General self-care agency related to all eight universal self-care requisites and self-efficacy for healthy eating behavior were both expected to influence the level of healthy eating behavior of MI patients.

Related literature

The relationship between self-care agency and self-care is a central premise in Orem’s (1985, 1991) theory. Several nursing studies demonstrated a positive correlation between self-care agency and self-care (Davidson, 1988; Denyes, 1988; Greenfield, 1989; Simmons, 1990). All of these studies were based on healthy individuals rather than those with cardiac disease, suggesting a need for further exploration of the concepts in MI patients. Theoretical and operational definitions of self-care agency in previous studies were related to general agency for self-care behavior rather than specific agency for nutritional self-care. No measure of agency for nutritional self-care was found.

Regarding self-efficacy, health care research reviewed by O’Leary (1985), Lawrance and McLeroy (1986) and Strecher et al. (1986) found strong relationships between self-efficacy

ORE&l-BASED NURSING INTERVENTION 261

and performance of health care behaviors such as weight loss, exercise, or smoking. Studies designed to modify health habits related to eating (Bernier and Avard, 1986; Chambliss and Murray, 1979; Jeffrey et al., 1984) consistently found self-efficacy positively related to successful weight control.

Studies of self-efficacy and nutritional self-care in cardiac patients had more varied results. Jenkins (1986) used a longitudinal, descriptive design to study self-efficacy and self- care in patients recovering from MI. Significant increases in confidence in ability were found over time for all five study behaviors, one of which was following a healthy diet. However, scores on self-reported performance of self-care behaviors did not increase significantly for nutritional self-care.

Gortner et al. (1988) conducted a randomized trial to investigate the effectiveness of a nursing intervention designed to increase self-care behaviors related to diet, exercise and stress management in cardiac surgery patients and their spouses. Three months post- surgery, the only statistically significant difference in the expected direction between exper- imental and control groups was on perceived self-efficacy for lifting. At 6 months, there were no significant differences between groups on either self-efficacy or self-care activities. The relationship between self-efficacy and nutritional self-care in cardiac patients remains unclear.

What constitutes healthy nutritional self-care in MI patients is related to the advice of health care authorities. Recommendations regarding a healthy diet for MI patients are based on research on primary and secondary prevention of cardiac disease.

Secondary prevention of cardiac disease involves measures designed to delay the progression of atherosclerosis and to prevent recurrent events in patients with manifestations of coronary artery disease (Wenger, 1986). Diet plays a central role in this approach. Clinical trials dealing with secondary prevention of heart disease (Arntzenius et al., 1985; Blankenhorn et al., 1987; Burr et al., 1989; Leren, 1989; Ornish et al., 1990; Watts et al., 1992) demonstrated that management of even moderately elevated serum cholesterol through diet can benefit patients with heart disease. The benefit was clear in studies using angiography to measure changes in atherosclerosis. When end points such as cardiac events or cardiac deaths were used, the benefit was also clear. Only when the end point-mortality from all causes-was used (Burr et al., 1989) was there any ambiguity about the benefit of a lipid-lowering diet.

For primary prevention of the occurrence of cardiac disease, Health and Welfare Can- ada’s (Health and Welfare Canada, 1990) nutritional recommendations for adults include: the fat content of the diet should constitute no more than 30% of total energy; only 10% of caloric requirements should be made up of saturated fats; cholesterol intake should remain below 300 mg per day; calories should not exceed the amount needed to meet energy requirements; dietary fiber should be increased, and sodium intake should be reduced. Guidelines from the American Heart Association Nutrition Committee (1988) for healthy Americans are similar to the Canadian guidelines.

For MI patients, secondary prevention is pertinent, therefore, it is particularly important that they meet at least the minimum nutritional recommendations for the general public. In the present study, nursing intervention aimed to assist patients to meet the minimum requirements for a heart healthy diet as recommended by North American health care authorities.

Nursing intervention studies which focused on the problem of modifying life style related to nutritional self-care in cardiac patients were reviewed. These studies failed to provide


clear evidence of the effectiveness of intervention on dietary behavior (Miller et al., 1988, 1990; Scalzi et al., 1980; Sivarajan et al., 1983; Steele and Ruzicki, 1987). These studies suggested that providing too much information may be overwhelming (Miller et al., 1988; Scalzi et al., 1980; Sivarajan et al., 1983) and that the timing of a teaching program is important. Inpatient teaching for MI patients may be poorly retained (Scalzi et aE., 1980) but 30 days after hospital discharge may be too late to have impact (Miller et al., 1988, 1990). Based on these findings, intervention in the present research was timed to take advantage of optimum patient readiness to receive and retain information the first week after discharge from hospital following the MI.

Method

Sample

Patients hospitalized with a myocardial infarction (the first within the past 5 years) were asked to consent to participate in the study. The sample included 62 men and 42 women who ranged in age from 34 to 83 years (M = 62, SD = 11 years). Ninety-eight of the subjects had just experienced their first MI, while the remaining eight had experienced a previous MI more than 5 years ago. Twenty of the subjects were diabetic, and 39 were classified as overweight based on body mass index of greater than 27.3 for females or greater that 27.8 for males (Whitney et al., 1990). There was a wide range of socioeconomic status measured with Blishen and McRoberts’ (1976) scale of socioeconomic status in Canada, but the majority (60%) of the subjects were from the lower socioeconomic groups.

Measures

Nutritional self-care was measured two ways, with a diet record and with a questionnaire on dietary patterns. For the diet record, patients were asked to write down everything they ate each day for three 24-hour periods. Daily food intake records provide a means of calculating nutrients in the diet and assessing adherence to a dietary regimen. Because of day-to-day variability in food intake, these records provide only estimates of intakes. Most individuals require assistance in order to record accurately with adequate detail. To clarify patient recording in this study, a home visit was considered necessary. Diet records are, however, considered the most accurate way of collecting data on dietary behavior and are often used to validate other data collection techniques such as questionnaires which require less commitment from the respondent (Beresford et al., 1992). The West Diet Analysis program (Whitney et al., 1990) was used to computer analyze a 3-day food record for average daily nutrients. The program first provides daily nutrient requirements for individuals based on ranges of age, activity level, height, and weight. It then analyzes nutrient intake for each day to give information on the percentage of the requirements the intake has provided.

The second measure of nutritional self-care was the food habits questionnaire (FHQ) which was developed to measure dietary patterns related to selecting low-fat diets (Kristal et al., 1990). Respondents are asked how often in the past month they did the eating behaviors. There are 20 items answered on a scale of 1 (usually) to 4 (never) or a ‘not applicable’ response. The dimensions of dietary behavior assessed include: modifying meat;

OREM-BASED NURSING INTERVENTION 263

avoiding high-fat foods; substituting specially manufactured low-fat foods for their higher fat counterparts; replacing high-fat foods with low-fat alternatives; and increasing intake of fruit and vegetables. A lower score suggests healthy eating, while a higher score suggests unhealthy eating patterns.

Test-retest reliability over an g-day period for 99 women was 0.87 and internal consistency was 0.62 for the total scale. Validity was tested against 4-day food records and a food frequency questionnaire and correlation was found to be high (r=0.68, P<O.OOl, Kristal et al., 1990). In the current study, test-retest reliability for 20 subjects tested 1 week apart was 0.91 for the total scale and Cronbach’s alpha for internal consistency for the whole sample was 0.74 at Time 1 and 0.77 at Time 2.

Self-care agency (SCA) was measured with the appraisal of self-care agency (ASA) scale (Isenberg et al., 1987). The ASA scale is based on the assumption that there are two elements of self-care agency, power components and self-care operations, neither of which can stand in isolation. The scale is intended to measure the power to perform self-care actions related to eight universal self-care requisites for general health and well-being (Orem, 1991). The scale contains 24 items rated on five-point Likert scales. Total scores can range from 24 (low SCA) to 120 (high SCA).

Internal consistency measured with coefficient alpha was reported to range from 0.77 to 0.86 with samples of cardiac surgery patients (Isenberg, 1987) or of elderly individuals (Achterberg et al., 1990; Lorensen et al., 1993). Evers (1987) reported evidence of short- term stability of 0.72 for a 7-week interval on the ASA in a Dutch study of elderly subjects. In the current study, test-retest reliability of the ASA for 20 subjects tested 1 week apart was 0.71. Internal consistency (coefficient alpha) for 104 subjects was 0.77 at Time I and 0.75 at Time 2.

Self-efficacy for health eating was measured with the Eating Habits Confidence Scale (EHCS; Sallis et al., 1988). This instrument was developed so that the items reflect confidence in one’s capability to perform the micro-behaviors that make up larger dietary habits. The EHCS contains 20 items which address four factors: (1) resisting relapse; (2) reducing calories; (3) reducing salt; and (4) reducing fat. Subjects are asked to rate how confident they are that they could really motivate themselves to do things like these consistently, for at least 6 months. Ratings are on a five-point Likert-like scale from (1) “I know I cannot” to (5) “I know I can”.

Sallis and colleagues (Sallis et al., 1988) reported that criterion-related validity was tested using analysis of a food frequency questionnaire for 39 food items rated by a dietitian as being either heart healthy, e.g. low in saturated fat and/or sodium, or not heart healthy. All factors were significantly correlated with the dietary index. Internal consistency reliability for the initial 69-item questionnaire was high, ranging from 0.85 to 0.93. Test& retest reliability over a 2-week period was lower, ranging from 0.43 to 0.64. Reliability of the 20-item version was not reported.

Test-retest reliability for the EHCS in the current study measured on 20 subjects 1 week apart was 0.97 for the 20-item scale. Internal consistency (coefficient alpha) was 0.83 for the whole scale at Time 1 and was 0.84 at Time 2.

Procedure

Subjects who had experienced a myocardial infarction were contacted in one of two community, general hospitals used for the study. Informed consent procedures were then


completed and the subjects were randomly assigned to a treatment or control group. The Time 1 interview to collect baseline data on self-care agency, self-efficacy for healthy eating, and food habits took place in the hospital for both groups. Treatment group subjects were then visited in their homes the week after they were discharged from hospital to begin the nursing intervention. Treatment group patients were asked to record food intake before this visit so the 3-day diet records could be collected. During the next 6 weeks, all subjects received three follow-up phone calls. The Time 2 interview with both groups for data on self-care agency, self-efficacy for healthy eating, and food habits took place in the home approximately 7 weeks after hospital discharge and the 3-day diet record was collected from both groups.

Nursing intervention protocol

Assessment of nutritional self-care was based on Orem’s (1991) recommendation that nursing attention should be directed towards discovering information about current or past self-care behavior. During the nursing intervention home visit to the treatment group, data from the hospital interview on food habits and from the 3-day diet record (before analysis) were used, along with observation and questioning, to determine dietary behavior related to food selection, meal preparation, and eating out with friends. All patients received a booklet about how to modify life style following MI before leaving hospital. Patients were asked if they had any questions about this written material as it related to their diets. Guidelines for lowering animal fat and all fat in the diet were emphasized and the fiber content of various foods was discussed. Examples from their own diet records were used to illustrate positive and negative habits.

Orem (1991) states that authoritative sources should be used to establish levels of self- care. For nutritional self-care this was done by using the guidelines established for the heart healthy diet (Health and Welfare Canada, 1990). Analysis of the 3-day diet record provided information about daily total fat and saturated fat intakes as percent of caloric intake and on daily intake of cholesterol and fiber. What the patient ate was compared with the nutritional goals for a heart healthy diet and the patient was informed by telephone about the extent to which goals were being met. If dietary changes were needed, alternative ways of achieving changes were suggested and an attempt was made to get commitment on the part of the patient to make the changes.

Healthy self-care behavior related to diet was recognized and encouraged in the initial home visit and in three follow-up telephone calls over the next 6 weeks. The importance of taking care of oneself at this point in the recovery period was emphasized.

The control group did not receive the intervention home visit and so were able to complete the diet record only on the Time 2 home visit 7 weeks after hospital discharge. The three follow-up phone calls to control subjects did not deal with diet unless the patient introduced the subject.

Data analysis

Data were analyzed using the Statistical Package for Social Sciences (SPSS). Significance level for all statistical analyses was set at PsO.05. Differences between treatment and


control groups were analyzed with t-tests, the chi square statistic, or repeated measures analysis of variance. The whole sample was examined for correlations among the variables.

Results

Control and treatment groups were compared on the measures of self-care agency, self- efficacy, and food habits at Time 1, the hospital interview. No significant differences were found between groups on any of the Time 1 measures using non-directional t-tests.

Groups were compared on nutritional self-care outcomes post intervention 7 weeks after hospital discharge (Time 2). Significant differences between groups were found on the diet record of total fat and saturated fat, and on the food habits questionnaire (FHQ) scores, but there was no significant difference between groups on diet record of cholesterol intake (Table 1).

The frequency of subjects in each group who met dietary recommendations for fat and cholesterol intake was calculated from the Time 2, 3-day diet record data (Table 2). The

Table 1. Comparison of treatment and control group means on 3-day diet record data and food habits questionnaire, 7 weeks after discharge from hospital, directional t-test between groups

Treatment group Control group (N=52) (N= 52)

Mean Mean (range) SD (range) SD t

Total fat percentage of calories Saturated fat percentage of calories Cholesterol (mg) Food habits questionnaire

26.40(1641) 5.60 32.38(2148) 6.33 -5.10* 8.82(419) 2.86 11.08(624) 3.58 -3.56* 178.85(83490) 82.68 206.10(755688) 102.74 - 1.49 2.15(1.553.35) 0.45 2.29(1.553.00) 0.35 - 1.78**

Note: SD = Standard deviation.*P<O.Ol; **P<O.O5.

Table 2. Frequency of subjects in treatment and control groups who met recommended diet goals post-intervention 7 weeks after discharge from hospital

Treatment N=52

Control N=52

Cholesterol less than 300 mg Total fat less than 30% Saturated fat less than 10%

49 48 0.15 38 21 11.32* 36 25 4.80**

*p<o.o1: **p<o.o5


Table 3. Pre-intervention (Time 1) and post-intervention (Time 2) appraisal of self-care agency (ASA) and eating habits confidence scale (EHCS) means in treatment and control

groups, non-directional t-tests for paired groups

Time 1 Time 2 (in hospital) (7 weeks later)

Mean SD Mean SD t

ASA Treatment group 90.12 10.56 93.61 8.78 -2.43* Control group 91.52 10.22 91.37 8.61 0.10 EHCS Treatment group 3.83 0.42 4.20 0.52 -6.11** Control group 4.00 0.53 4.18 0.48 -2.16*

Note: SD= standard deviation. *P<O.O5; **PiO.Ol.

number of patients who met the recommendations for total and saturated fat was significantly higher in the treatment group but there was no significant difference between groups regarding the number who met recommendations for cholesterol intake.

Treatment and control groups were examined for changes over time on self-care agency and self-efficacy for healthy eating (Table 3). Between the Time 1 hospital interview and the interview 7 weeks later, the treatment group significantly increased both self-care agency and self-efficacy for healthy eating. The control group increased only their self-efficacy during this period.

At Time 2, there were no significant differences between the group means on measures of either self-care agency or self-efficacy. When Time 1 and Time 2 data were examined using repeated measures analysis of variance, the group by time interaction failed to reach the PcO.05 level of significanceforeitherASA[F(l, 102)=3.03]; or EHCS [F(l, 102)= 3.651. Thus the change over time did not significantly distinguish between groups.

The theoretical framework suggested that self-care agency and self-efficacy for heart healthy eating behaviors and were two characteristics of patients which might affect their level of nutritional self-care post MI regardless of intervention. Correlations between measures of these variables and nutritional self-care post-hospital discharge were done using the whole sample of 104 subjects (see Table 4).

Correlations between the measure of self-efficacy for eating habits (the EHCS) and nutritional self-care were generally stronger compared to correlations with the measure of self-care agency for general self-care behavior (the ASA scale). Time 2 correlations were generally higher than those at Time 1 because they represent cross-sectional data measured in the same interview. Time 1 correlations represent prospective, longitudinal relationships because they relate to diet behavior measured 7 weeks later.

Discussion

The use of Orem’s conceptual framework was appropriate in meeting the aims of this study. Nursing intervention following guidelines provided in Orem’s theory was effective


Table 4. Correlations between appraisal of self-care agency (ASA) scores, and the eating habits confidence survey (EHCS), with nutritional self-care measures, 7 weeks after discharge from hospital (N= 104)

ASATime 1 ASATime 2 EHCSTime 1 EHCSTime 2

Percentage total fat

-0.03 - 0.09 -0.12 -0.22*

Percentage saturated

fat

-0.12 -0.14 - 0.20* -0.30**

Cholesterol

-0.01 -0.22* -0.10 -0.26**

Food habits

questionnaire

-0.25* -0.28** -0.39** -0.50**

Note: Time I =in hospital; Time 2=7 weeks post-intervention. *P<O.O5; **P<O.Ol

in supporting healthy eating behavior in myocardial infarction patients. The nursing system encouraged patients to take care of themselves, particularly regarding the self-care requisite for a healthy diet. Consolvo (1990) suggested that people seem most willing to consider changing their diets during pregnancy and after a heart attack. At this point in their lives, patients in this study appeared open to suggestions related to their eating habits as part of their self-care.

Orem’s guideline indicating a need for individuals to understand the level of their self- care requisites seemed particularly appropriate for myocardial infarction patients. Sorting out conflicting reports and advice about healthy diets was confusing for many of the patients and their families. Serum cholesterol levels were not available at the time of hospital discharge because of the lack of accuracy of cholesterol measurements in the early period following myocardial infarction (Cooper et al., 1988; Gore et al., 1984). Patients were unsure how important it was to reduce dietary fat because, without knowing serum cholesterol levels, physicians often failed to provide specific dietary advice. Perhaps because of this ambiguity, the information provided by the investigator appeared to be particularly pertinent. It was possible to analyze the patient’s diet and provide specific feedback about the extent to which heart healthy dietary recommendations for fat and cholesterol content were being met. This made understanding the nutritional self-care requisite relatively clear for the patient. Although patients responded to the nursing intervention by lowering their consumption of total fat and of saturated fat, there was no apparent change in cholesterol consumption. Both treatment and control group means for cholesterol intake were well below the recommended 300 mg, leaving little room for improvement in either group. Public information appears to be successful regarding the danger of excessive dietary cholesterol but less so regarding total fat and animal fat. This suggests a continuing need for patient support, as dietary fat has been found to be highly correlated with serum cholesterol (American Heart Association Nutrition Committee, 1988).

The nature of the relationship between self-care agency and nutritional self-care was expected to be positive but moderate because nutrition is only one of eight aspects of self- care addressed in the instrument used. Findings related to the sample as a whole were consistent with this expectation and provide support for the positive relationship theorized by Orem between self-care agency and self-care and found in previous studies (Davidson, 1988; Greenfield, 1989; Simmons, 1990).


The finding that self-care agency increased in the treatment group but not in the control group suggested that the effect of the nursing action was partly related to its influence on self-care agency. This occurred in spite of the fact that the intervention focused on only one specific aspect of self-care related to nutrition.

Concepts from the psychological theory of self-efficacy were less useful in this study. Self-efficacy in the total sample was correlated with measures of dietary outcomes and self-efficacy appeared to increase over time. However, measures of self-efficacy did not differentiate the treatment from the control group. The nursing intervention appeared to have little impact on confidence related to eating habits. This may have been because the confidence level of both groups was quite high, leaving little room for improvement. Patients also appeared reluctant to admit areas in which they felt a lack of confidence. According to Bandura (1977) performance feedback is the strongest influence on levels of self-efficacy, while verbal persuasion is the weakest. In this study, treatment group patients received only one instance of performance feedback through the diet analysis. Perhaps in a situation where longer follow-up with more frequent feedback on performance related to eating habits was possible, nursing intervention would have more impact on self- efficacy.

In conclusion, this study used Orem’s conceptual framework to design and evaluate nursing intervention to support nutritional self-care of post myocardial infarction patients. Orem’s model proved highly useful in guiding strategies for planning effective care, as well as contributing to explanations of how the intervention worked.

References

Achterberg, T. van Lorensen, M., Isenberg, M., Evens, G., Levin, E. and Philipsen, H. (1990). The Norwegian, Danish and Dutch version of the appraisal of self-care agency scale; comparing reliability aspects. Stand. J. Caring Sci. 5, 101~108.

American Heart Association Nutrition Committee (1988). Dietary guidelines for healthy American adults: a statement for physicians and health professionals. Circulation 77(3), 721 A-724A.

Arntzenius, A., Kromhout, D., Barth, J., Reiber, J., Bruschke, A., Buis, B., van Gent, C., Kempen-Voogd, N., Strikwerda, S. and Van Der Velde, E. (1985). Diet, lipoproteins and the progression of coronary atherosclerosis: the Leiden Intervention Trial. New Engl. J. Med. 312, 805-8 11.

Bandura, A. (1977). Self-efficacy: toward unifying theory of behavioral change. Psychol. Rev. 84, 191-215. Bandura, A. (1986). The explanatory and predictive scope of self-efficacy theory. J. Social Cl&. Psychol. 4, 3%

373. Beresford, S., Farmer, E., Feingold, L., Graves, K., Sumner, S. and Baker, R. (1992). Evaluation of a self-help

dietary intervention in a primary care setting. Am. J. Publ. Health 82, 79-84. Bernier, M. and Avard, J. (1986). Self-efficacy, outcome and attrition in a weight-reduction program. Cognit.

Ther. Res. 10, 319-338. Blankenhorn, D., Nessim, S., Johnson, R., Sanmarco, M., Azen, S. and Cashin-Hemphill, L. (1987). Beneficial

effects of combined colestipol-niacin therapy on coronary atherosclerosis and coronary venous bypass grafts. 1. Am. Med. Assoc. 257, 3233-3240.

Blishen, B. and McRoberts, H. (1976). A revised socioeconomic index for occupations in Canada. Cnn. Rec. Social. Anthropol. 13(l), 71-73.

Burr, M. L., Gilbert, J. F., Holliday, R. M., Elwood, P. C., Fehily, A. M., Rogers, S., Sweetnam, P. M. and Deadman, N. M. (1989). Effects of changes in fat, fish and tibre intakes on death and myocardial reinfarction: diet and reinfarction trial (DART). Lancet 2 (8666), 757-761.

Chambliss, C. and Murray, E. (1979). Efficacy attribution, locus of control and weight loss. Cognit. Ther. Res. 3. 349-353.

0 REM-BASED NURSING INTER VENTION 269

Consolvo, D. A. (1990). Efficacy and administration of cardiac rehabilitation: a review. J. Cardiopulm. Rehahil. 10,24&254.

Cooper, G. R., Myers, G. L., Smith, S. J. and Sampson, E. J. (1988). Standardization of lipid, lipoprotein and apohpoprotein measurements. Clin. Chem. 34, B955B105.

Davidson, J. (1988). The relationship between self-care agency and health-promoting behaviors (unpublished). Dissrrt. Abstr. Int. 49, 3102B.

Denyes. M. (1988). Orem’s model used for health promotion: directions from research. Adv. Nurs. Sci. 11, 13-21.

Evers, G. (1987). Reliability and validity of appraisal of self-care agency scale, abstracted. In Proceedings of/he International Nursing Research Cocfkrence, Nursing Advances in Health. Arlington. Vermont.

Gore, J. M., Goldberg, R. J., Matsumoto. A. S., Castelli, W. P., McNamara, P. M. and Dalen, J. E. (1984). Validity of serum total cholesterol level obtained within 24 hours of acute myocardial infarction. Am. J. Cardiol. 54, 722 -725.

Gortner, S., Gilliss, C., Shinn, J., Sparacino, P., Rankin, S., Leavitt. M., Price, M. and Hudes. M. (1988). Improving recovery following cardiac surgery: a randomized clinical trial. J. Ado. Nurs. 13, 649-661.

Greenfield, P. H. (1989). A comparison of the self-care ability of employed women who have and have not maintained weight loss (unpublished). Dissert. Absfr. Int. 50 088, 3398.

Health and Welfare Canada. (1990). Nutrition Recommendations: The Report of the Scient$c Reuiek Committee. Author, Ottawa.

Isenberg, M. (1987). International research project to test Orem’s self-care deficit theory of nursing. Proceedings of Scientific Session of the 29th Biennial Convention of Sigma Theta Tau Iniernutional. Sigma Theta Tau, San Francisco.

Isenberg, M., Evers, G. and Brouns. G. (1987). An international research project to test Orem’s self-care deficit theory. Proceedings qf the International Research Congress. University of Edinburgh, Edinburgh, Scotland.

Jeffrey, R., Bjornson-Benson. W., Rosenthal, B., Lindquits, R., Kurth, C. and Johnson, S. (1984). Correlates of weight loss and its maintenance over two years of follow-up among middle-aged men. Precent. Med. 13, 155- 168.

Jenkins, L. (1986). Self-efficacy: new perspectives in caring for patients recovering from myocardial infarction, Prog. C’ardiocasc. Nurs. 2, 32-35.

Kristal, A., Shattuck, A. and Henry, H. (1990). Patterns of dietary behavior associated with selecting diets low in fat: reliability and validity of a behavioral approach to dietary assessment, J. Am. Dietet. Assoc. 90, 214220.

Lawrance, L. and McLeroy, K. (1986). Self-efficacy and health education. J. School Health 56, 317-321. Leren, P. (1989). Prevention of coronary heart disease: some results from the Oslo sxondary and primary

intervention studies. J. Am. Coil. Nutrit. 8. 407410. Lorensen. M., Halter, I., Evers, G., Isenberg, M. and Achterberg, T. van (1993). Cross-cultural testing of the

“appraisal of self-care agency”: ASA Scale in Norway. Int. J. Nurs. Stud. 30, 15-23. Miller, P., Wikoff, R., Garrett. M., McMahon, M. and Smith, T. (1990). Regimen compliance two years after

myocdrdiat infarction. Nurs. Res. 39. 333~~336. Miller, P.. Wikoff, R.. McMahon, M., Garrett, M. and Ringel, K. (1988). Influence of a nursing intervention on

regimen adherence and societal adjustments postmyocardial infarction. Nurs. Res. 37, 297-302. Neville. J. (1990). On matters of the heart: past, present and future. J. Am. Dietet. Assoc. 90, 21 I-213. O’Leary, A.. Self-efficacy’ Health. Behuo. Rey. Ther. (1985). 23.437451. Orem, D. (1985). I&rsing Concepts ofPractice, 3rd Edn. McGraw-Hill. New York. Orem, D. (1991). Nursing Concepts qfPractice, 4th Edn. Mosby, St. Louis. Ornish, D., Brown, S., Scherwitz, L., Billings, J., Armstrong, W., Ports, T., McLanahan, S., Kirkeeide, R., Brand,

R. and Gould. K. (1990). Can lifestyle changes reverse coronary heart disease?. Lance/ 336, 1299133. Sallis. J., Pinski, R., Grossman, R., Patterson, T. and Nader, P. (1988). The development of self-efficacy scales

for health-related diet and exercise behaviors. Heulth Educ. Res. 3, 283-292. Scalzi, C., Burke, L. and Greenland. S. (1980). Evaluation of an inpatient educational program for coronary

patients. Heart and Lung 9, 846-850. Simmons. S. J. (1990). Self-care agency and health-promoting behavior of a military population (unpublished).

Dissert. Abstr. Int. 51 05B, 2290. Sivarajan. E., Newton, K.. Almes, M., Kempf, T., Mansfield, L. and Bruce, R. (1983). Limited effects ofoutpatient

teaching and counselling after myocardial infarction: a controlled study. Heart and Lung 12, 65-73. Steele, J. and Ruzicki, D. (1987). Patient teaching: an evaluation of the effectiveness of cardiac teaching during

hospitahzation. Heart and Lung 16, 3063 Il. Strecher, V.. Becker, M., DeVellis, B. and Rosenstock, 1. (1986). The role of self-efficacy in achieving health

behavior change. Health Educ. Q. 13, 73-91. Watts, G. F., Lewis, B., Brunt, J. N., Lewis. E. S., Coltart, D. J., Smith, L. D., Mann, J. I. and Swan, A. V.

(1992). Effects on coronary artery disease of lipid-lowering diet, or diet plus cholestyramine, in the St. Thomas’ Atherosclerosis Regression Study (STARS). Lancet 339 (8803) 1241-1242.


Wenger, N. K. (1986). Rehabilitation of the coronary patient: Status 1986. Prog. Cardiovasc. Dis. 29(3), 181-204.

Whitney, E., Hamilton, E. and Rolfes, S. (1990). Understanding Nutrition, 5th Edn. West Publishing Company, St. Paul.

(Received 16 February 1995; in revisedform 30 August 1995; accepted 13 September 1995)