Methods and Limitations
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Methodology

We estimated the percentage of American adults with diabetes who take insulin or oral medication for their diabetes using data from the National Health Interview Survey (NHIS) of the National Center for Health Statistics (NCHS), Centers for Disease Control and Prevention (CDC). NHIS is a health survey of the civilian, noninstitutionalized, household population of the United States that has been conducted since 1957. The survey provides information on the health of the U.S. population, including information on the prevalence and incidence of disease, extent of disability, and use of health care services. The multistage probability design of the survey has been described elsewhere.1

Adult respondents were asked whether a health professional had ever told them they had diabetes. To exclude gestational diabetes, the NHIS asked women whether they had been told they had diabetes other than during pregnancy. Those with diabetes were asked: "Are you now taking insulin?" and "Are you now taking diabetic pills to lower your blood sugar? These are sometimes called oral agents or oral hypoglycemic agents."

Responses to these questions were used to determine the percentage of adults with diabetes who take insulin or oral medication for their diabetes. Adults with diabetes by medication use were categorized into the following four groups: those taking only insulin, those taking only oral medications, those taking both, and those not taking any. Respondents who reported taking either insulin, or pills, or both were considered as those taking “any diabetes medication.”

Estimates of the percentage of adults with diabetes taking diabetes medication are presented by age, sex, and race/ethnicity. Three-year averages were used to improve the precision of the annual estimates. Persons of Hispanic origin may be of any race. The racial groups include persons of both Hispanic and non-Hispanic origin. The 2000 U.S. population was used as the standard to conduct age-adjusted estimates.
 

Limitations

Estimates of the proportion of persons with diabetes but unaware because their diabetes has not been diagnosed—range from approximately one-fourth2 to approximately one-third.3 The NHIS data reflects medication use only among those with self-reported diagnosed diabetes.
 

References

  1. Botman SL, Moore TF, Moriarity CL, Parsons VL. Design and estimation for the National Health Interview Survey, 1995–2004. National Vital and Health Statistics, Series 2, Data from the National Health Survey. 2000;130(2).
  2. Centers for Disease Control and Prevention. National Diabetes Fact Sheet: General Information and National Estimates on Diabetes in the United States, 2007. Atlanta, GA: Centers for Disease Control and Prevention, U.S. Department of Health and Human Services; 2008.
  3. Cowie CC, Rust KF, Byrd-Holt DD, et al. Prevalence of diabetes and impaired fasting glucose in adults in the U.S. population: National Health And Nutrition Examination Survey 1999–2002. Diabetes Care. 2006;29(6):1263-1268.