Multiple Chronic Conditions in the United States · This chartbook assesses the prevalence of multiple chronic conditions in the United States and explores the associated health care

A

C O R P O R A T I O N

Multiple Chronic Conditions in the United States

Christine Buttorff, Teague Ruder, and Melissa Bauman

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I

In 2014, 60 percent of Americans had at least one chronic

condition, and 42 percent had multiple chronic conditions.

These proportions have held steady since 2008. Americans

with chronic conditions utilize more—and spend more on—

health care services and may have reduced physical and

social functioning. This chartbook updates previous versions

with more recent data on the prevalence of multiple chronic

conditions (2008–2014) and associated health care utilization

and spending. It explores disparities in the prevalence of chronic

conditions and associated utilization of health care services and

analyzes functional or other limitations for those with multiple

chronic conditions. This chartbook should be of interest to

researchers, policymakers, and practitioners, as well as to the

general public.

The authors would like to thank the Partnership to Fight Chronic

Disease for providing support for this project. We also thank our

reviewers, Chloe E. Bird, Ph.D., and Gerard F. Anderson, Ph.D.,

for lending their expertise to this report.

This research was conducted in RAND Health, a division of

the RAND Corporation. A profile of RAND Health, abstracts of its

publications, and ordering information can be found at

www.rand.org/health.

Preface

iii

II

Contents

Preface ................................................................................................................................................. iii

Figures and Tables ................................................................................................................................v

Introduction ...........................................................................................................................................1

Methodology .........................................................................................................................................3

Chapter 1: Prevalence of Multiple Chronic Conditions .........................................................................5

Chapter 2: Health Service Use and Spending ...................................................................................13

Chapter 3: Functional Status of Adults with Multiple Chronic Conditions ..........................................18

Appendix: Detailed Methodology and Limitations .............................................................................21

References ..........................................................................................................................................27

iv

iii

Figures and Tables

Figure 1.1. Percentage of U.S. Adults with Chronic Conditions, by Number of Chronic

Conditions (2014) ...............................................................................................................................6

Figure 1.2. Prevalence of Multiple Chronic Conditions, by Age (2008–2014) ..........................................7

Figure 1.3. Prevalence of Multiple Chronic Conditions by Age and Gender (2014) ................................8

Figure 1.4. Percentage of U.S. Adults with One or More Chronic Conditions by

Race/Ethnicity (2014) .........................................................................................................................9

Figure 1.5. Prevalence of Top Chronic Conditions, 2014 ........................................................................10

Figure 1.6. Most Common Chronic Conditions in 2008 and 2014, Men ................................................11

Figure 1.7. Most Common Chronic Conditions in 2008 and 2014, Women ...........................................12

Figure 2.1. Annual Service Utilization by Number of Chronic Conditions (2014) ...................................14

Figure 2.2. Prevalence and Spending by Number of Chronic Conditions (2014) ..................................15

Figure 2.3. Health Care Spending by Number of Chronic Conditions (2014) ........................................16

Figure 2.4. Average Annual Health Care Expenditures, by Number of Chronic Conditions

and Insurance Type .........................................................................................................................17

Figure 2.5. Out-of-Pocket Spending by Number of Chronic Conditions and Insurance Type ..............17

Figure 3.1. Functional, Physical, Social, and Cognitive Limitations, by Number of Chronic

Conditions (2014) .............................................................................................................................19

Figure 3.2. ADL, Instrumental ADL, and Cognitive Limitations by Age and Number of Chronic

Conditions (2014) .............................................................................................................................20

Figure A.1. Prevalence of Multiple Chronic Conditions (2003–2014) .....................................................25

Figure A.2. Prevalence of Multiple Chronic Conditions in Adults Age 65 and Older, 2008–2013 ........26

Table A.1. Decision Rules for Imputing Masked Conditions ...............................................................22

v

1

Introduction

Six in ten adult Americans had at least one chronic condition

in 2014, the latest year for which data are available, and

four in ten had more than one. As this chartbook shows, chronic

disease is a burden not only for these patients but also for the

health care system overall. Those with multiple chronic conditions

have poorer health, use more health services, and spend more

on health care—trends that have been stable since 2008.

This chartbook assesses the prevalence of multiple chronic

conditions in the United States and explores the associated

health care utilization and medical spending. This version

updates and expands on previous editions: the Agency for

Healthcare Research and Quality’s (AHRQ’s) 2014 edition of

the Multiple Chronic Conditions Chartbook,10 as well as previous

iterations from the Robert Wood Johnson Foundation and Johns

Hopkins University.11, 12

The data confirm that the prevalence of multiple chronic

conditions—that is, having two or more chronic diseases

simultaneously—is highest among older adults. It also shows

that women are more likely than men to have multiple chronic

conditions, as many women live longer than men do. The

What is a chronic condition?

A chronic condition is a physical

or mental health condition that

lasts more than one year and

causes functional restrictions or

requires ongoing monitoring or

treatment.7

When a patient has more than one

chronic condition—for example,

diabetes, hypertension, and

mood disorders—treatment can

be difficult to manage. Treatment

strategies or drug regimens

may be similar—but can be

very different—and one chronic

condition may be better managed

than the others.1

Introduction | 1

2

prevalence of multiple chronic conditions is higher in non-

Hispanic whites than in other racial/ethnic groups, which may

reflect differences in access to care, rather than in the actual

prevalence of chronic disease. In addition, those with more

conditions have greater reported functional, social, and cognitive

limitations.

For policymakers, planning for the care of people with complex

chronic conditions is increasingly urgent as baby boomers

become eligible for Medicare. Previous work has shown that

people with multiple chronic conditions face more financial

obligations and functional limitations2, 3 and often have worse

health outcomes.4, 5, 6 Other work has shown that people with

multiple chronic conditions have higher hospital readmission

rates7 and much higher health care expenses.8 Multiple physical

health conditions can be difficult to manage, especially when

coupled with depression or other mental health conditions. In

addition, younger generations can be affected by the financial

and social implications of caring for the millions of older

Americans.9

Introduction | 2

3

Methodology

This study uses the Medical Expenditure Panel Survey

(MEPS) from AHRQ.13 MEPS is a publicly available, nationally

representative sample of the U.S. civilian, noninstitutionalized

population. It is important to note that institutionalized adults are

excluded from the charts because they are not included in the

MEPS data.

For the purposes of this chartbook, we define multiple chronic

conditions as having two or more conditions. We used the MEPS

survey weights to create nationally representative estimates.

We attempted to replicate the methods of earlier chartbooks.

Similar to previous iterations, this version identifies distinct

conditions using the Clinical Classification Software codes that

are part of the MEPS dataset, which group individual International

Classification of Diseases, ninth edition (ICD-9) diagnosis codes

into distinct conditions.14 To identify which conditions are chronic,

we used the Chronic Conditions Indicator, developed by Hwang

and colleagues.15, 16

Most of the charts in this book use data from 2014, the most

recent year available for adults 18 and older. In the 2007–2008

panels, MEPS added a set of questions specifically asking

whether respondents had certain priority conditions; as a

result, there is a marked increase in the reported prevalence of

chronic conditions overall at this point. Therefore, we restrict the

presentation of trends in prevalence of chronic conditions over

time to 2008–2014.

Our results have several limitations that should be taken into

account when using charts from this publication. The results may

underestimate the prevalence of chronic conditions because

the data do not include individuals living in institutions, who

Methodology | 3

4

may have a larger number of chronic conditions. While the

population of institutionalized adults is small for those ages

18–64, older adults are more likely to be in long-term care

facilities, so we may underestimate the prevalence among older

adults. About 3 percent of adults 65 and older were in full-year

long-term nursing care facilities in 2013, the latest year for

which data are available from the Medicare Current Beneficiary

Survey.17 Because MEPS is a survey that relies on respondents

to report on their own health, the data may also underrepresent

the actual prevalence of chronic disease if individuals are not

aware that they have the condition. We can only measure the

prevalence of those who have been treated or told by a health

care provider that they have a chronic condition (also called

the “treated prevalence”). Finally, it has been documented

elsewhere that MEPS underestimates total spending on health

care services, and the underestimate can be as much as

17.6 percent, depending on the service type.18 The estimates

on average spending should, therefore, be interpreted with

caution. Despite these limitations, MEPS is one of the best

sources of data on U.S. health care utilization, spending,

access to care, insurance coverage, and demographic

information.

A full description of the methodology can be found in the

appendix.

Methodology | 4

5

Prevalence of Multiple Chronic Conditions

CHAPTER 1

6

As of 2014, 60 percent of American adults had at least one chronic condition, and 42 percent had more than one chronic condition.

NOTE: Percentages may not total 100 because of rounding.

Figure 1.1. Percentage of U.S. Adults with Chronic Conditions, by Number of Chronic

Conditions (2014)

42% had more than one chronic condition 60% had at least

one chronic condition

12% of U.S. adults had five or more chronic conditions

CHAPTER 1 | Prevalence of Multiple Chronic Conditions | 6

40%had no chronic

conditions

18%

13%

9%

7%

12%

5+

4

3

2

Number of chronic conditions

1

0

7

The prevalence of multiple chronic conditions is higher among older adults.

PE

RC

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TAG

E O

F A

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WIT

H M

ULT

IPL

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HR

ON

IC C

ON

DIT

ION

S

90

2008 2009 2010 2011 2012 2013 2014

80

70

60

50

40

30

20

10

0

81%

50%

18%

42%

Figure 1.2. Prevalence of Multiple Chronic Conditions, by Age (2008–2014)

YEAR


65 years and older

45–64 years

Overall

18–44 years

Over time, the prevalence of U.S. adults with multiple chronic conditions has remained steady, at

around 42 percent.

8

Women ages 18 through 64 have a higher prevalence of multiple chronic conditions than men.

Figure 1.3. Prevalence of Multiple Chronic Conditions by Age and Gender (2014)

90

18–44 years

80

70

60

50

40

30

20

10

0

45–64 years 65 years and over

14%

22%

54%

47%

82% 81%

The presence of multiple chronic conditions increases with age for both genders. Because our

estimates of prevalence are based on self-reported conditions, we do not know if the higher

prevalence among women is a result of true differences in prevalence or of other factors, such as

women being more likely to be diagnosed because they may visit their health care providers more

often.19

Gender gapJust over 100 million people have multiple chronic conditions, and 54 million of them are women.

MEN

WOMEN

PE

RC

EN

TAG

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F A

DU

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WIT

H M

ULT

IPL

E C

HR

ON

IC C

ON

DIT

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S


9

PE

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TAG

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F A

DU

LTS

WIT

H O

NE

OR

MO

RE

CH

RO

NIC

CO

ND

ITIO

NS

Non-Hispanic whites have a higher reported prevalence of chronic conditions than other racial or ethnic groups.

Figure 1.4. Percentage of U.S. Adults with One or More Chronic Conditions by Race/Ethnicity (2014)

The difference between racial/ethnic groups for those with one chronic condition varies from a high of 63 percent for non-Hispanic whites to a low of 49 percent for Hispanics.

70

Non-Hispanic white

60

50

40

30

20

10

0

Non-Hispanic black

Non-Hispanic other

HIspanic

63%

58%

50%49%

NOTE: Estimates have been age-adjusted for the overall U.S. age distribution.

One reason could be that nonwhite racial/ethnic groups have historically had less access to

insurance and health care services, making it less likely that their conditions would be diagnosed

or treated. The non-white population is also younger; however, we do age-adjust the data.


14-point gap across racial/ethnic groups

10

Figure 1.5. Prevalence of Top Chronic Conditions, 2014


Hypertension and high cholesterol were the most common chronic conditions in 2014.

Heavy on heart disease One in four U.S. adults has hypertension, and about one in five has high cholesterol.

Hypertension

Lipid disorders (e.g., high cholesterol)

Inflammatory joint disorders (other than arthritis)

Osteoarthritis

Asthma

Coronary atherosclerosis and other heart disease

0 5 10 15 20 25 30PERCENTAGE

Mood disorders (e.g., depression, bipolar disorder)

Diabetes mellitus

Anxiety disorders (e.g., anxiety, panic disorders, stress)

Other upper respiratory disorders (e.g., chronic

laryngitis, chronic sinusitis)

27.0%

21.6%

11.9%

10.4%

9.7%

7.4%

7.4%

6.5%

6.3%

4.8%

11


Figure 1.6. Most Common Chronic Conditions in 2008 and 2014, Men

MEN

The prevalence of hypertension increased by 2.5 percentage points for men, and anxiety disorders

increased by 4.4 percentage points for women. The reported prevalence of mental health

conditions also increased from 2008 to 2014.

Hypertension


Diabetes mellitus


Coronary atherosclerosis and other heart disease


Other upper respiratory disorders (e.g., chronic

laryngitis, chronic sinusitis)

Anxiety disorders (e.g., anxiety, panic disorders,

stress)

Asthma

Other upper respiratory infections (e.g., specific

types of chronic sinusitis)

0 5 10 15 20 25 30

24.9%27.4%

22.3%23.0%

2008

2014

9.2%10.5%

6.6%8.6%

6.4%5.8%

6.1%6.6%

5.9%5.8%

4.4%6.3%

4.3%4.5%

3.8%3.9%

PERCENTAGE

For women, the prevalence of anxiety disorders increased the most between 2008 and 2014, while hypertension increased the most for men.

2.5-percentage-point increase in hypertension among men

*

*

*

*

* Differences are significant at the p < 0.05 level or below.

12

WOMEN

Hypertension



Other upper respiratory disorders (e.g., chronic laryngitis, chronic sinusitis)

Diabetes mellitus

Anxiety disorders (e.g., anxiety, panic disorders, stress)

Osteoarthritis


Asthma

Other upper respiratory infections (e.g., specific types of chronic sinusitis)

30 25 20 15 10 5 0

26.5%26.5%

21.8%20.3%

12.9%15.1%

9.3%9.0%

9.3%10.3%

8.4%12.8%

8.2%8.7%

7.8%8.2%

7.2%8.0%

7.2%6.7%


PERCENTAGE

2008

2014

* Differences are significant at the p < 0.05 level or below.

4.4-percentage-point increase in anxiety disorders among women

Figure 1.7. Most Common Chronic Conditions in 2008 and 2014, Women

*

*

*

*

*

From these data, we are unable to determine whether the apparent uptick in reported mental health

conditions reflects an increase in diagnosis and reporting (possibly stemming from a decrease in

stigma) or an increase in the prevalence of the diseases.

13

Health Service Use and Spending

CHAPTER 2

14

CHAPTER 2 | Health Service Use and Spending | 14

Health service use and spending is higher for those with chronic conditions than for those who are healthy.

Figure 2.1. Annual Service Utilization by Number of Chronic Conditions (2014)

The more chronic conditions people have, the more they use services of all types. As one example,

those with five or more chronic conditions use twice as many drugs on average per year, compared

with those with three or four conditions. As another, people with five or more conditions averaged 20

doctor visits per year, compared with 12 visits for those with three or four conditions.

3–4

EMERGENCY DEPARTMENT VISITS

PE

RC

EN

TAG

E W

ITH

AT

LE

AS

T O

NE

ED

VIS

IT

1–20 5+

35

30

25

20

15

10

5

0

32%

20%

14%

7%

OUTPATIENT VISITS

AV

ER

AG

E N

UM

BE

R O

F V

ISIT

S

3–41–20

25

20

15

10

5

5+0

20

12

6

2

PRESCRIPTIONS

AV

ER

AG

E N

UM

BE

R O

F

PR

ES

CR

IPT

ION

S F

ILL

ED

3–41–20

60

50

40

30

20

10

5+0

51

24

9

1

INPATIENT STAYS

PE

RC

EN

TAG

E W

ITH

AT

LE

AS

T O

NE

IN

PA

TIE

NT

STA

Y

3–41–20 5+

24%

10%

6%

3%

NOTES: Average utilization is presented; not everyone uses a particular service in a given year, especially inpatient stays and ED visits. The number of prescriptions represents the total number of fills, including refills, not necessarily unique active ingredients, such as acetaminophen or ibuprofen.

NUMBER OF CHRONIC CONDITIONS

35

30

25

20

15

10

5

0


NUMBER OF CHRONIC CONDITIONS NUMBER OF CHRONIC CONDITIONS

15

Americans with five or more chronic conditions make up 12 percent of the population but account for 41 percent of total health care spending.

Figure 2.2. Prevalence and Spending by Number of Chronic Conditions (2014)

90

Total population

80

70

60

50

40

30

20

10

0Total expenditures

PE

RC

EN

TAG

E

NOTE: Total health care spending defined as the amount spent on all outpatient and inpatient health care services across all payers, including out-of-pocket payments.

Percentages may not total 100 because of rounding.

100

12%

16%

31%

40%

41%

26%

23%

10%

5+

3–4

1–2

0

Number of chronic conditions


16

People with chronic conditions have higher health care spending.

Figure 2.3. Health Care Spending by Number of Chronic Conditions (2014)

Those with five or more chronic conditions spend twice as much on average as those with three

or four conditions, with the majority of that additional spending going to office visits, inpatient

visits, and prescriptions.

20,000

0

18,000

14,000

12,000

10,000

8,000

6,000

4,000

2,000

0

AV

ER

AG

E A

NN

UA

L S

PE

ND

ING

PE

R P

ER

SO

N IN

DO

LL

AR

S

NOTE: Total health care spending is defined as the amount spent on health care services across all payers, including patient out-of-pocket payments.

Average utilization is presented; not everyone uses a particular service in a given year, especially inpatient stays and ED visits.

1–2 3–4 5+

16,000

Other

Home health

Prescription

ED

Office and outpatient

Inpatient


14 times more spending On average, Americans with five or more chronic conditions spend 14 times more on health services than people with no chronic conditions.


17


Spending on health care services increases with number of chronic conditions but varies by insurance type.

Figure 2.4. Average Annual Health Care Expenditures, by Number of Chronic

Conditions and Insurance Type

Figure 2.4 displays payments for health care spending from other payers, such as Medicare or private

insurance. An important caveat is that this figure does not account for other social supports to manage

chronic conditions, such as unpaid caregiving from family members.

Medicare

Other public

Private

5+

3–4

1–2

0

Number of chronic conditions0 25,000

DOLLARS

20,00015,00010,0005,000

$17,640

$8,867

$5,272

$1,973

$20,763

$9,864

$4,107

$1,397

$18,351$8,349

$4,241

$1,533

0

DOLLARS

Medicare

Other public

Private

$1,792

$1,137

$741

$378

$808

$640

$242

$92

$1,741

$1,201

$698

2,000 1,000 750 500 2501,750 1,500 1,250

$295

Figure 2.5 Out-of-Pocket Spending by Number of Chronic Conditions and

Insurance Type

18

CHAPTER 3

Functional Status of Adults with Multiple Chronic Conditions

19

CHAPTER 3 | Functional Status of Adults with Multiple Chronic Conditions | 19

Individuals with more chronic conditions have greater difficulties with activities of daily living (ADL) and other social and cognitive functions that are important to patients’ independence.

People with five or more conditions have more than double the number of these limitations than those with

three or four conditions, and the greater functional limitations place higher demands on caregivers and the

health care system.

NOTES: ADL include such basic functions as being able to bathe, dress, eat, go to the bathroom, or do light activity—for example, walking up a flight of stairs. Instrumental ADL include light housework, preparing meals, paying bills, and shopping. We used the composite variables constructed in MEPS for the ADL and IADL, which indicate whether a person reported needing supervision to complete at least one ADL or instrumental ADL activity. A work/school/home limitation is defined as an impairment or a physical or mental health problem that limits a person’s ability to work at a job, do housework, or go to school. A physical limitation is defined as having difficulties walking, climbing stairs, grasping objects, bending, or standing for long periods of time. MEPS defines social limitations as whether a person has trouble participating in social or family activities because of a physical or cognitive impairment. A cognitive limitation exists if the person has trouble with memory, is easily confused, has trouble making decisions, or needs to be supervised for his or her own safety.

3–4

NEED HELP WITH ADL

1–20 5+

11%

3%1%0%

60

50

40

30

20

10

0

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TAG

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F U

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DU

LTS

Figure 3.1. Functional, Physical, Social, and Cognitive Limitations, by Number of Chronic Conditions (2014)

WORK/HOME/SOCIAL LIMITATIONS

3–41–20 5+

42%

19%

6%

1%

60

50

40

30

20

10

0

3–4

PHYSICAL LIMITATIONS

1–20

60

50

40

30

20

10

5+0

51%

25%

9%

2%


PE

RC

EN

TAG

E O

F U

.S. A

DU

LTS

NEED HELP WITH INSTRUMENTAL ADL

3–41–20 5+

18%

6%2%0%

60

50

40

30

20

10

0

PE

RC

EN

TAG

E O

F U

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DU

LTS

PE

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EN

TAG

E O

F U

.S. A

DU

LTS

3–41–20 5+

23%

10%

3%1%

60

50

40

30

20

10

0

SOCIAL LIMITATIONS

PE

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EN

TAG

E O

F U

.S. A

DU

LTS


COGNITIVE LIMITATIONS

3–41–20 5+

23%

10%

4%1%

60

50

40

30

20

10

0

PE

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TAG

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NUMBER OF CHRONIC CONDITIONS NUMBER OF CHRONIC CONDITIONS NUMBER OF CHRONIC CONDITIONS

20

Older adults have more limitations on their daily activities and cognitive health than younger people.

Figure 3.2. ADL, Instrumental ADL, and Cognitive Limitations by Age and Number of Chronic

Conditions (2014)

INSTRUMENTAL ADL LIMITATIONS

3–41–20 5+

3–4

COGNITIVE LIMITATIONS

1–20

25

20

15

10

5

5+0

3–4

ADL LIMITATIONS

1–20 5+

25

20

15

10

5

0

PE

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EN

TAG

E O

F U

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25

20

15

10

5

00%

2%

1%

5%

3%

4%

13%

9%

0%

3%

1%

7%

4%

9%

21%

14%

1%

4%3%

8%10%

10%

25%

21%

25 percent of adults under age 65 with five or more chronic conditions have cognitive limitations.

18–64 years

65 years and over

Age

CHAPTER 3 | Functional Status of Adults with Multiple Chronic Conditions | 20

PE

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NUMBER OF CHRONIC CONDITIONS NUMBER OF CHRONIC CONDITIONS

PE

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21

Appendix Detailed Methodology and Limitations

Data and Chronic Condition Identification

We used data from MEPS, a nationally representative

survey of U.S. health and health care use administered by

AHRQ.13 Most charts use data from 2014; charts that compare

the change in the treated prevalence of conditions over time

use data from 2008 through 2014. We use the term treated

prevalence to indicate that the data are survey-reported and

therefore may underestimate the true prevalence of a given

disease. Similar to previous chartbooks, we use the Clinical

Classification Software (CCS), which groups individual

ICD-9 codes into clinically distinct conditions, such as “essential

hypertension,” publicly available from the Healthcare Cost and

Utilization Project.14 Chronic conditions were identified with

Dr. Wenke Hwang’s publicly available Chronic Condition

Indicator, which was also used for previous chartbooks.6, 16, 21

In contrast with the previous chartbook, we did not group

together distinct CCS categories. Our results are similar

even without grouping together such categories as essential

hypertension (CCS 98) and hypertension with complications

(CCS 99). A complete listing of ICD-9 codes associated with

each CCS category is available from the Healthcare Cost and

Utilization Project: https://www.hcup-us.ahrq.gov/toolssoftware/

ccs/AppendixASingleDX.txt.

For each person, we assigned a chronic condition indicator for

the given CCS category if at least one of their ICD-9 codes in the

CCS category was labeled as chronic in the Chronic Condition

Indicator. This avoided overcounting multiple ICD-9s within the

same CCS category. For example, if a person had two ICD-9s

within the essential hypertension category (CCS 98), they were

only counted as having one chronic condition of hypertension.

Appendix | 21

22

Most of the ICD-9s within a given category for the top ten chronic

conditions are chronic in the CCI. There are a few, such as other

upper respiratory infections, that have a smaller proportion of

chronic ICD-9s within the CCS category.

Beginning in 2013, MEPS began masking certain three-digit

ICD-9 codes in the medical condition file to protect individuals

with rare conditions from possible identification. For a given

observation, the CCS code is available, but the ICD-9 codes

may be missing. The percentages of masked patient conditions

were 6.1 percent in 2013 and 9.2 percent in 2014, as compared

with less than 1 percent in 2012. The missing ICD-9s caused

drops in the prevalence of certain conditions in 2013 and 2014

compared with previous years, since we were identifying chronic

conditions from the ICD-9 level. While most CCS categories are

considered entirely chronic or non-chronic, the masking makes

it difficult to identify chronic conditions within CCS categories

that have a mix of chronic and non-chronic conditions. To impute

these masked conditions, we first calculated the percentage of

the CCS category that was considered chronic using historical

MEPS condition data from 2003 to 2012. We then used the

decision rules shown in Table A.1 to determine whether a

condition would be deemed chronic or non-chronic.

Appendix | 22

Table A.1. Decision Rules for Imputing Masked Conditions

Percentage of Cases Within the

CCS Category That Were Chronic

Conditions in 2003–2012

Number of CCS

Categories

Number of Observations

(2013)

Number of Observations

(2014)Decision

Rule

90–100% 37 2,573 2,651 Chronic

10.1–89.9% 30 612 1,108 Non-chronic

0–10% 76 3,909 6,477 Non-chronic

23

As a sensitivity analysis, we tested assigning the middle category

of cases (10.1 percent to 89.9 percent) to chronic instead of non-

chronic. Because of the relatively small sample size of this group,

the impact on our outcome measure of an individual’s number of

chronic conditions was small. For example, the percentage of the

population with at least one chronic condition in 2013 was

60.18 percent (if we assigned all middle cases to non-chronic)

and 60.45 percent (if we assigned all middle cases to chronic),

for a difference of just 0.27 percent. We set middle-category

cases to non-chronic to provide a conservative estimate

of chronic conditions. The decision rule for this set of CCS

categories was then applied across all years of data to ensure

the comparability of estimates from one year to the next.

Therefore, our estimates may differ slightly from the estimates

published in prior chartbooks. The list of CCS categories with

missing ICD-9 codes is available from the authors upon request.

Limitations

While MEPS is one of the best national sources of health care

spending and health status, it is important to highlight that it is

a survey. As such, the data are potentially biased, particularly

when it comes to underreporting health conditions. Because

MEPS is a survey, chronic conditions are self-identified;

therefore, prevalence estimates from MEPS represent the treated

prevalence of a disease, which may be lower than the actual

prevalence. As a result, there are notable differences between

the treated prevalence for a given condition and the actual

prevalence measure in datasets with a laboratory component,

such as the National Health and Nutrition Examination

Survey (NHANES). For example, the proportion of adults with

hypertension in NHANES is 29 percent (2011–2014) versus our

estimate of approximately 26 percent for men and women for

2014.22

Appendix | 23

24

Two other limitations of note: The first is that MEPS only surveys

civilian and noninstitutionalized Americans. As a result, we are

missing the treated prevalence of disease in these groups.

However, because the proportion of institutionalized adults

is small, this may not markedly affect results. The Medicare

Current Beneficiary Survey reports that approximately 3 percent

of beneficiaries were in a long-term care facility in 2013.17 The

second limitation is that MEPS likely underreports medical

spending by about 17.6 percent, compared with the National

Health Expenditures Accounts available from CMS, due to

differences in the populations covered and services that are

included in the totals and even in service category definitions.18

These limitations have been documented elsewhere by Bernard

et al. (2012),18 and we highlight them so that readers interpret our

results with caution.

As seen in Figure A.1, there is a marked uptick in the treated

prevalence of chronic conditions between 2006–2007 and 2007–

2008, likely caused by a change in the questionnaire at that time

to include a section on “priority conditions,” which directly asks

respondents if a doctor has ever told them that they have a given

disease. Previously, respondents would have had to volunteer

the information. For this reason, we have limited our comparisons

over time to 2008–2014.23

Appendix | 24

25

Figure A.1. Prevalence of Multiple Chronic Conditions (2003–2014)

PE

RC

EN

TAG

E O

F U

.S. A

DU

LTS

WIT

H M

ULT

IPL

E C

HR

ON

IC C

ON

DIT

ION

S90

2003

60

50

40

30

20

10

0

2004 2005 2006

80

70

YEAR

2007 2008 2009 2010 2011 2012 2013 2014

NOTE: This figure documents the prevalence of multiple chronic conditions (two or more) by age group. The trend lines break at 2007 to indicate that MEPS changed its approach to the chronic disease questions.

Comparison of the Trends in Chronic Disease in MEPS to Other Sources

Our estimates of the trend in chronic condition prevalence

are flat for the period 2008–2014. This is consistent with other

national datasets, notably the Medicare population from data

tables of chronic conditions for fee-for-service beneficiaries

from the Centers for Medicare & Medicaid Services (CMS) and

the National Health Interview Survey (NHIS), both of which are

publicly available (Figure A.2).24, 25 We did not examine particular

individuals over time to determine whether they experienced

more chronic conditions. While the prevalence has remained

stable over time, the absolute numbers may have increased—

particularly for older Americans, as the baby-boomer generation

becomes eligible for Medicare.

81%

50%

18%

Appendix | 25

65 years and older

45–64 years

18–44 years

26

Figure A.2. Prevalence of Multiple Chronic Conditions in Adults

Age 65 and Older, 2008–2013P

ER

CE

NTA

GE

OF

U.S

. AD

ULT

S A

GE

65

AN

D O

LD

ER

WIT

H M

ULT

IPL

E C

HR

ON

IC C

ON

DIT

ION

S 90

2008 2009 2010 2011 2012 2013

60

50

40

30

20

10

0

80

70

YEAR

SOURCE: Publicly available data on the prevalence of having two or more chronic conditions from NHIS, MEPS, and CMS for those age 65 and older.

81%

70%

66%

61%

Our estimates of the treated prevalence of disease are slightly

higher than the CMS estimates for the prevalence of multiple

chronic conditions for the population of those age 65 and older

and are higher than the NHIS estimates. The differences are

likely due to the number of chronic conditions included in the

counts. We used the full list of chronic conditions corresponding

to the granular CCS categories. The CMS analysis limits its

analysis to 19 conditions, and NHIS limits its analysis to ten.

Appendix | 26

MEPS

CMS, women

CMS, men

NHIS

27

References

References | 27

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28

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References | 28

Photo credits: Cover, WavebreakMediaMicro/Fotolia | page 1, Dean Mitchell/Getty Images | page 2, Syda Productions/Fotolia | page 4, Viacheslav Iakobchuk/Fotolia | page 5, bowdenimages/Getty Images | page 14, fstop123/Getty Images | page 19, diego_cervo/Fotolia.

Multiple Chronic Conditions in the United States · This chartbook assesses the prevalence of multiple chronic conditions in the United States and explores the associated health care

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