NCHS Data Brief ■ No. 57 ■ January 2011

u.s. department of health and human services

Centers for Disease Control and Prevention

National Center for Health Statistics

Lack of health insurance presents a barrier to obtaining routine preventive 

care and early diagnosis and management of chronic conditions. In 2005–

2008, approximately 23% of adults aged 20–64 had no health insurance. 

Hypercholesterolemia (high total cholesterol or taking medication to lower 

cholesterol) and hypertension (high blood pressure or taking medication 

to lower blood pressure) are major risk factors for cardiovascular disease, 

particularly when untreated and uncontrolled (1,2) and are common 

among nonelderly adults. In 2005–2008, 23% of adults aged 20–64 had 

hypercholesterolemia and 23% had hypertension. The objective of this 

report is to quantify the association between health insurance coverage and 

the diagnosis and control of hypercholesterolemia and hypertension among 

persons with those conditions. The criteria used to define these conditions are 

provided in the “Definitions” section of the report.

Keywords: health care access • high total cholesterol • high blood pressure • 

National Health and Nutrition Examination Survey

Adults with health insurance are more likely to be tested for 

high cholesterol than those without insurance.

Key findings

Data from the National 

Health and Nutrition 

Examination Survey 

(NHANES), 2005–2008

• Nonelderly adults with 

health insurance were more 

likely to have had a test for 

high cholesterol in the past 

5 years compared with those 

with no insurance.

• Hypercholesterolemia was 

undiagnosed among almost 

one-half of nonelderly adults 

with the condition who lacked 

health insurance—about twice 

the percentage for those who 

had insurance. 

• Hypertension was 

undiagnosed among about 

40% of nonelderly adults with 

that condition who lacked 

health insurance—about twice 

the percentage for those with 

insurance.

• Control of hypercholesterolemia and hypertension 

was also negatively affected 

by lack of health insurance, 

primarily due to the greater 

prevalence of undiagnosed 

conditions among those 

without insurance.

Health Insurance Affects Diagnosis and Control of 

Hypercholesterolemia and Hypertension Among

Adults Aged 20–64: United States, 2005–2008

Susan E. Schober, Ph.D.; Diane M. Makuc, Dr.P.H.; Cindy Zhang, M.D., M.P.H.;

Jocelyn Kennedy-Stephenson, M.S.; and Vicki Burt, Sc.M., R.N. Percent

Figure 1. Screening for high cholesterol in the last 5 years among adults aged 20–64, by 

insurance coverage and age: United States, 2005–2008

† Significantly different from those with private health insurance and those with public health insurance.

§

 Significantly different from those with private health insurance.

NOTE: Access data table for Figure 1 at: http://www.cdc.gov/nchs/data/databriefs/db57_tables.pdf#1.

SOURCE: CDC/NCHS, National Health and Nutrition Examination Survey, 2005–2008.

72.2

55.8

83.4

67.6

46.5

83.0

37.1

26.8

52.2

0

20

40

60

80

100

Total (20–64 years) 20–39 years 40–64 years

Private insurance Public insurance No insurance

†

†

†

§
NCHS Data Brief ■ No. 57 ■ January 2011

■  2  ■

• In 2005–2008, nonelderly adults aged 20–64 with either private or public health insurance 

were almost twice as likely to have had their blood cholesterol checked in the past 5 years 

compared with those with no coverage (Figure 1).

• Among adults aged 40–64 with private or public health insurance, approximately 83% had 

received the recommended blood cholesterol screening in the past 5 years. In contrast, 52% 

of uninsured persons in this age group received the recommended screening. Younger adults 

were less likely to be screened than older adults.

Hypercholesterolemia is more likely to be uncontrolled, and more likely to 

be undiagnosed, among uninsured adults with the condition than among 

those with health insurance.

• Among nonelderly adults with hypercholesterolemia, the condition was uncontrolled for 

approximately 80% of those with no health insurance, compared with about 60% of those 

with private or public health insurance (Figure 2). 

• Control of hypercholesterolemia varied by insurance coverage status only among adults 

aged 40–64. Among adults 20–39, the percentage with uncontrolled hypercholesterolemia 

did not differ by health insurance coverage. In addition, those 20–39 were more likely than 

those in the older age group to have uncontrolled hypercholesterolemia, regardless of health 

insurance coverage.

• Differences in the control of hypercholesterolemia between insured and uninsured adults 

were primarily related to differences in the diagnosis of the condition. Among nonelderly 

Figure 2. Uncontrolled hypercholesterolemia among adults aged 20–64 with hypercholesterolemia, by insurance coverage 

and age: United States, 2005–2008 Percent

0

20

40

60

80

100

Diagnosed and

uncontrolled

Undiagnosed

61.6

57.7

81.5

85.7 87.3

93.8

55.7

50.8

75.5

†

†

Private insurance Public insurance No insurance

† Significantly different from those with private health insurance and those with public health insurance.

NOTE: Access data table for Figure 2 at: http://www.cdc.gov/nchs/data/databriefs/db57_tables.pdf#2.

SOURCE: CDC/NCHS, National Health and Nutrition Examination Survey, 2005–2008.

Total (20–64 years) 20–39 years 40–64 years
NCHS Data Brief ■ No. 57 ■ January 2011

■  3  ■

adults who had hypercholesterolemia, the condition was undiagnosed among 48% of those 

who were uninsured, compared with 27% of those with private and 25% with public health 

insurance. In contrast, the condition was diagnosed but currently not adequately controlled 

among approximately one-third of all nonelderly adults with the condition, and there was no 

difference in the percentage among those with private, public, or no health insurance.

Hypertension is more likely to be uncontrolled, and more likely to be 

undiagnosed, among uninsured adults with the condition than among 

those with health insurance.

• Among nonelderly adults with hypertension, the condition was uncontrolled among 71% 

of those with no health insurance, compared with 52% of those with private and 45% with 

public insurance (Figure 3).

• Control of hypertension was more likely among those with private or public insurance, 

compared with those with no insurance, for persons of both age groups (20–39 and 40–64 

years), but 20–39 year olds were more likely to lack control than those aged 40–64. 

• Similar to the results for hypercholesterolemia, differences in the control of hypertension 

between insured and uninsured adults were primarily related to differences in the 

diagnosis of the condition. Among nonelderly adults with hypertension, the condition was 

undiagnosed among 40% of the uninsured—a rate approximately twice that for those with 

either private or public insurance. However, hypertension was diagnosed but currently 

uncontrolled among approximately 30% of all nonelderly persons with the condition, and 

there was little difference between those with and without health insurance coverage. 

Figure 3. Uncontrolled hypertension among adults aged 20–64 with hypertension, by insurance coverage and age:

United States, 2005–2008 Percent

Diagnosed and

uncontrolled

Undiagnosed

Private insurance Public insurance No insurance

0

20

40

60

80

100

51.8

44.6

71.3

64.6

50.8

83.0

49.8

43.6

67.9

†

†

†

Total (20–64 years) 20–39 years 40–64 years

† Significantly different from those with private health insurance and those with public health insurance.

NOTE: Access data table for Figure 3 at: http://www.cdc.gov/nchs/data/databriefs/db57_tables.pdf#3.

SOURCE: CDC/NCHS, National Health and Nutrition Examination Survey, 2005–2008.
NCHS Data Brief ■ No. 57 ■ January 2011

■  4  ■

More than one in six adults with either hypercholesterolemia or 

hypertension have no health insurance coverage.

• In 2005–2008, 18% of adults aged 20–64 with hypercholesterolemia or hypertension, or 

both, had no health insurance, 68% had private health insurance, and 14% had public health 

insurance (Figure 4). 

• Among those with either or both of these conditions, adults aged 20–39 were more likely to 

be uninsured (25%) than those 40–64 (15%). 

• Nonelderly adults with either or both of these conditions were less likely to be uninsured 

(18%) than all nonelderly adults (23%) (data not shown). 

Summary

In 2005–2008, 23% of adults aged 20–64 had hypercholesterolemia and 23% had hypertension. 

The prevalence was higher among adults 40–64 (33% for hypercholesterolemia and 36% for 

hypertension) than among those 20–39 (10% and 8%, respectively). Overall during this period, 

lack of health insurance coverage was associated with poorer rates of diagnosis and control of 

hypercholesterolemia and hypertension among nonelderly U.S. adults with these conditions. 

Uninsured persons with each of these conditions were about twice as likely to be undiagnosed 

as those who had private or public coverage. Among persons with hypercholesterolemia, the 

condition was uncontrolled among 81% of uninsured persons, compared with 61% of those with 

private coverage and 58% with public coverage. Similarly, among those with hypertension, 71% 

of the uninsured group had uncontrolled hypertension compared with 52% of the private and 

45% of the public coverage groups. The association of insurance coverage with the diagnosis and 

control of hypercholesterolemia was found only among those aged 40–64 and not in the younger 

age group. In contrast, the association of insurance coverage with the diagnosis and control of 

hypertension was found for both the younger and older age groups.

Figure 4. Health insurance coverage among adults aged 20–64 with hypercholesterolemia or hypertension, by age:

United States, 2005–2008 Percent

Private insurance Public insurance No insurance

68.3

14.2 17.5

61.2

13.6

25.2

70.2

14.4 15.4

0

20

40

60

80

100

†

†

Total (20–64 years) 20–39 years 40–64 years

† Significantly different from those aged 20–39.

NOTE: Access data table for Figure 4 at: http://www.cdc.gov/nchs/data/databriefs/db57_tables.pdf#4.

SOURCE: CDC/NCHS, National Health and Nutrition Examination Survey, 2005–2008.
NCHS Data Brief ■ No. 57 ■ January 2011

■  5  ■

Hypercholesterolemia and hypertension were uncontrolled in more than one-half of nonelderly 

adults with each condition, regardless of health insurance coverage, even though therapies are 

available that adequately control these conditions (1,2). Lack of control may be due to many 

factors, including that the conditions are not diagnosed or are inadequately treated, or because 

of poor compliance with prescribed therapy (whether lifestyle changes or medication). The 

higher percentages of adults with uncontrolled conditions among those without health insurance 

than among those with health insurance are explained in large part by higher percentages of 

undiagnosed conditions among uninsured adults. 

Nonelderly adults without health insurance coverage were also less likely to have received 

recommended screening for high cholesterol. One objective of the Healthy People 2010 initiative 

was to increase to at least 80% the proportion of adults aged 18 and over who have been screened 

for high cholesterol in the last 5 years (3). This level of screening was attained among persons 

aged 40–64 who had either private or public insurance but was not met for uninsured adults in 

that age group or for younger adults regardless of insurance coverage. Another Healthy People 

2010 objective was to increase to 95% the proportion of adults 18 and over who have had their 

blood pressure checked by a health professional in the last 2 years and can state whether their 

blood pressure is normal or high (3). In 2008, adults 18–64 with private or public insurance 

(94%–95%) were closer to attaining this target than those with no insurance (82%) (National 

Health Interview Survey, unpublished data). 

The definitions of hypertension and hypercholesterolemia used in this report are based on clinical 

measures and a history of currently taking medication for the respective conditions, consistent 

with current definitional guidelines (1,2). Expanding the definitions to include persons with 

nonpharmacological control of these conditions increases estimates of prevalence and control 

(4,5) but was not considered in this report. 

Other studies (see, for example, references 6–8) have examined the association of health 

insurance coverage with diagnosis and control of hypertension and hypercholesterolemia based 

on NHANES data, but in most cases definitions or target age groups differ, so results are not 

directly comparable with those reported here. A previous study based on NHANES III (1988–

1994) data found that nonelderly adults with hypertension and hypercholesterolemia (as defined 

in this brief) were much more likely to be undiagnosed if they were uninsured than insured, 

even after adjustment for sociodemographic characteristics. Three measures of access to care 

that are affected by health insurance coverage (having a regular site of care, a regular provider, 

and a recent health care contact) explained much of the difference in undiagnosed conditions by 

insurance status (9). This report provides continued evidence of the positive association of health 

insurance coverage with the diagnosis and control of hypertension and hypercholesterolemia. 

Definitions

Hypercholesterolemia: Blood total cholesterol level of 240 mg/dL or greater or currently taking 

cholesterol-lowering medication (based on positive responses to the following questions: 

“Have you ever had your blood cholesterol checked?”; “Have you ever been told by a doctor 

or other health professional that your blood cholesterol level was high?”; “To lower your blood 

cholesterol, have you ever been told by a doctor or other health professional to take prescribed 

medication?”; and “Are you now following this advice to take prescribed medication?”).
NCHS Data Brief ■ No. 57 ■ January 2011

■  6  ■

Undiagnosed hypercholesterolemia: A finding of hypercholesterolemia and never told by a health 

care provider that cholesterol was high (based on a negative response to the question, “Have you 

ever been told by a doctor or health professional that your blood cholesterol is high?”). 

Uncontrolled hypercholesterolemia: Blood total cholesterol level of 240 mg/dL or greater among 

those with hypercholesterolemia.

Screened for high cholesterol in the past 5 years: Based on an affirmative response to the 

question, “Have you ever had your blood cholesterol checked?” and response indicating less than 

5 years ago to the question, “About how long has it been since you last had your blood cholesterol 

level checked?”

Hypertension: Systolic blood pressure of 140 mm Hg or greater, or diastolic blood pressure of 

90 mm Hg or greater, or currently taking medication to lower blood pressure (based on positive 

responses to the following questions: “Have you ever been told by a doctor or other health 

professional that you had hypertension, also called high blood pressure?”; “Because of your [high 

blood pressure/hypertension], have you ever been told to take prescribed medicine?”; and “Are 

you now taking a prescribed medicine?”). 

Undiagnosed hypertension: A finding of hypertension and never told by a health care provider 

that blood pressure was high (based on a negative response to the question, “Have you ever been 

told by a doctor or other health professional that you had hypertension, also called high blood 

pressure?”). 

Uncontrolled hypertension: Systolic blood pressure of 140 mm Hg or greater, or diastolic blood 

pressure of 90 mm Hg or greater, among those with hypertension.

Health insurance coverage: At the time of interview. Private insurance excludes plans that pay for 

only one type of service, such as dental or vision care. Persons covered by both public and private 

plans are classified as having private coverage. Public coverage includes Medicaid, Children’s 

Health Insurance Program (CHIP), state-sponsored or other government-sponsored health plan, 

Medicare (disability), or military health care (TRICARE, VA, or CHAMP–VA). Uninsured 

persons do not have private or public coverage. 

Data source and methods

The National Health and Nutrition Examination Surveys (NHANES) conducted from 2005 

through 2008 were used for these analyses. NHANES is a cross-sectional survey designed to 

monitor the health and nutritional status of the civilian noninstitutionalized U.S. population 

(10). The survey consists of interviews conducted in participants’ homes, standardized physical 

examinations conducted in mobile examination centers, and laboratory tests utilizing blood and 

urine specimens provided by participants during the physical examination. 

The NHANES sample is selected through a complex, multistage design that includes selection of 

primary sampling units (counties), household segments within the counties, and, finally, sample 

persons from selected households. In 2005–2008, non-Hispanic black and Mexican-American 

persons, persons with low-income, and those aged 60 years and over were oversampled in order 

to obtain reliable estimates of health and nutritional measures for these population subgroups. 

In 2007–2008, all Hispanic persons were oversampled in addition to the oversampling of the 
NCHS Data Brief ■ No. 57 ■ January 2011

■  7  ■

Mexican-American population. In 1999, NHANES became a continuous survey fielded on an 

ongoing basis. Each year of data collection is based on a representative sample covering all ages 

of the civilian noninstitutionalized population. Public-use data files are released in 2-year cycles. 

Sample weights, which account for the differential probabilities of selection, nonresponse, and 

noncoverage, are incorporated into the estimation process. All variance estimates accounted for 

the complex survey design by using Taylor series linearization (11). Differences between groups 

were evaluated using a univariate t statistic. All significance tests were two-sided using p < 0.05 

as the level of statistical significance. All differences reported are statistically significant unless 

otherwise indicated. Adjustments were not made for multiple comparisons.

Statistical analyses were conducted using the SAS System for Windows (release 9.1; SAS 

Institute, Inc., Cary, North Carolina) and SUDAAN (release 9.0; Research Triangle Institute, 

Research Triangle Park, North Carolina). 

About the authors

Susan Schober and Vicki Burt are with the Centers for Disease Control and Prevention’s National 

Center for Health Statistics, Division of Health and Nutrition Examination Surveys. Diane Makuc 

is with the Centers for Disease Control and Prevention’s National Center for Health Statistics, 

Office of Analysis and Epidemiology. Cindy Zhang is with Harris IT Services. Jocelyn KennedyStephenson is with Northrop Grumman Corporation.

References

1. Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults. 

Executive summary of the Third Report of the National Cholesterol Education Program (NCEP) 

Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults (Adult 

Treatment Panel III). JAMA 285:2486–97. 2001.

2. Chobanian AV, Bakris GL, Black HR, et al. Seventh report of the Joint National Committee 

on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: The JNC 7 report. 

JAMA 289(19):2560–71. 2003.

3. U.S. Department of Health and Human Services. Healthy People 2010, 2nd ed, 2 vols. 

Washington, DC: U.S. Government Printing Office. 2000.

4. Cutler JA, Sorlie PD, Wolz M, Thom T, Fields LE, Roccella EJ. Trends in hypertension 

prevalence, awareness, treatment, and control rates in United States adults between 1988–1994 

and 1999–2004. Hypertension 52(5):818–27. 2008.

5. Hyre AD, Muntner P, Menke A, Raggi P, He J. Trends in ATP–III-defined high blood 

cholesterol prevalence, awareness, treatment, and control among U.S. adults. Ann Epidemiol 

17(7):548–55. 2007.

6. Duru OK, Vargas RB, Kermah D, Pan D, Norris KC. Health insurance status and 

hypertension monitoring and control in the United States. Am J Hypertens 20(4):348–53. 2007.
NCHS Data Brief ■ No. 57 ■ January 2011

First Class mAIL

Postage & Fees Paid 

CDC/NCHS

Permit No. G-284

U.S. Department of

Health & Human Services

Centers for Disease Control and Prevention

National Center for Health Statistics

3311 Toledo Road

Hyattsville, MD 20782

Official Business

Penalty for Private Use, $300

To receive this publication regularly, contact the 

National Center for Health Statistics by

calling 1–800–232–4636

E-mail: cdcinfo@cdc.gov

Internet: http://www.cdc.gov/nchs

ISSN 1941–4927 (Print ed.)

ISSN 1941–4935 (Online ed.)

CS219420

T38166 (1/2011)

DHHS Publication No. (PHS) 2011–1209

7. Ostchega Y, Hughes JP, Wright JD, McDowell MA, Louis T. Are 

demographic characteristics, health care access and utilization, and comorbid 

conditions associated with hypertension among US adults? Am J Hypertens 

21(2):159–65. 2008.

8. Wilper AP, Woolhandler S, Lasser KE, McCormick D, Bor DH, 

Himmelstein DU. Hypertension, diabetes, and elevated cholesterol among 

insured and uninsured U.S. adults. Health Aff 28(6):w1151–w1159. 2009.

9. Ayanian JZ, Zaslavsky AM, Weissman JS, Schneider EC, Ginsburg 

JA. Undiagnosed hypertension and hypercholesterolemia among uninsured 

and insured adults in the Third National Health and Nutrition Examination 

Survey. Am J Public Health 93(12):2051–4. 2003.

10. National Center for Health Statistics. National Health and Nutrition 

Examination Surveys, 2005–2008. Available from: http://www.cdc.gov/nchs/

nhanes/nhanes_questionnaires.htm. Accessed May 2010.

11. National Center for Health Statistics. National Health and Nutrition 

Examination Survey: Analytic guidelines. Available from: http://www.cdc.

gov/nchs/nhanes/nhanes2003-2004/analytical_guidelines.htm. Accessed May 

2010.

Suggested citation

Schober SE, Makuc DM, Zhang C, 

Kennedy-Stephenson J, Burt V. Health 

insurance affects diagnosis and control of 

hypercholesterolemia and hypertension 

among adults aged 20–64: United States, 

2005–2008. NCHS data brief, no 57. 

Hyattsville, MD: National Center for Health 

Statistics. 2011.

Copyright information

All material appearing in this report is in 

the public domain and may be reproduced 

or copied without permission; citation as to 

source, however, is appreciated.

National Center for Health 

Statistics

Edward J. Sondik, Ph.D., Director

Jennifer H. Madans, Ph.D., Associate 

Director for Science

Division of Health and Nutrition 

Examination Surveys

Clifford L. Johnson, M.S.P.H., Director

Office of Analysis and Epidemiology 

Linda T. Bilheimer, Ph.D., Director