The National Survey on Drug Use and Health (NSDUH) is an annual survey of the civilian, non-institutionalized population of the United States aged 12 years old or older. Prior to 2002, the survey name was the National Household Survey on Drug Abuse (NHSDA).
The survey presents National estimates and also offers estimates for States and areas within.
The survey has been conducted since 1971 (when it collected 3000) interviews and has expanded to include 68,308 completed interviews by 2005.
The survey uses a complex sampling design over sampling youths and young adults, so that in 2005, each State's sample was approximately equally distributed among three age groups:
12 to 17 years,
18 to 25 years, and
26 years or older.
The survey has reported State level estimates of alcohol, tobacco, and illegal drug use for all the individual States since 1999.
SAMHSA’s annual reports on State estimates use small area estimation (SAE) procedures that combine NSDUH data with local-area county and census block group/tract-level predictors of substance use.
SAMHSA reports that “This model-based methodology provides more precise estimates of substance use at the State level than those based solely on the sample, particularly for smaller States.” the same estimation method is used by SAMHSA to produce sub-State estimates in periodic reports.