Comparison of NSDUH Health and Health Care Utilization Estimates to Other National Data Sources

In addition to collecting data on substance use and mental health in the United States, the National Survey on Drug Use and Health also collects data on health conditions and health care utilization. It is important for users of these data to recognize how the NSDUH estimates differ from prevalence estimates produced by other nationally representative data sources, which have various objectives and scope, sampling designs, and data collection procedures. This report compares specific health conditions, overall health, and health care utilization prevalence estimates from the 2006 NSDUH and other national data sources. Methodological differences among these data sources that may contribute to differences in estimates are described. In addition to NSDUH, three of the data sources use respondent self-reports to measure health characteristics and service utilization: the National Health Interview Survey (NHIS), the Behavioral Risk Factor Surveillance System (BRFSS), and the Medical Expenditure Panel Survey (MEPS). One survey, the National Health and Nutrition Examination Survey (NHANES), conducts initial interviews in respondents’ homes, collecting further data at nearby locations. Five data sources provide health care utilization data extracted from hospital records; these sources include the National Hospital Discharge Survey (NHDS), the Nationwide Inpatient Sample (NIS), the Nationwide Emergency Department Sample (NEDS), the National Health and Ambulatory Medical Care Survey (NHAMCS), and the Drug Abuse Warning Network (DAWN). Several methodological differences that could cause differences in estimates are discussed, including type and mode of data collection; weighting and representativeness of the sample; question placement, wording, and format; and use of proxy reporting for adolescents. There were no differences between the lifetime estimate of diabetes among adults from NSDUH (7.7 percent) and the estimates from NHIS, NHANES, BRFSS, and MEPS. The lifetime estimate of asthma among adults from NSDUH (10.7 percent) was similar to the estimate from NHIS (11.0 percent); estimates from other sources ranged from 9.6 percent to 14.2 percent. The lifetime estimates of stroke and high blood pressure among adults from NSDUH were both lower than estimates from NHIS, NHANES, and MEPS, and there was considerable variation between surveys in the rate of lifetime heart disease. Estimates of past year inpatient hospitalization among adults did not differ significantly between NSDUH and NHANES, but NSDUH was significantly higher than the estimates derived from NHIS and MEPS. For both adults and adolescents, the NSDUH estimates of receiving treatment in an ER in the past year were higher than estimates from other surveys. Demographic differences in the prevalence of chronic health conditions and health care utilization were similar across multiple surveys. Given all of the methodological differences among these data sources, the similarities among estimates are noteworthy.