Data were collected by Research Triangle Institute, Research Triangle Park, NC, and prepared for release by National Opinion Research Center, Chicago, IL. For selected variables, statistical imputation was performed following logical imputation to replace missing responses. Unique code values were assigned to the recency-of-use variable when such logical imputation occurred. These code values are readily identifiable by the phrase "... LOGICALLY IMPUTED" or "... LOGICALLY ASSIGNED" in the code value descriptions. Data were weighted based on the three stages of sampling that were used. The person-level sampling weight is the product of the three-stage sampling weights, each of which is equal to the inverse of the selection probability for that stage. Adjustments were made to compensate for nonresponse and sampling error. Adjustments also included trimming sample weights to reduce excessive weight variation and a post-stratification to Census population estimates. To protect the anonymity of respondents, all variables that could be used to identify individuals have been deleted from the public use file. For some drugs that have multiple names, questions regarding the use of that drug may be asked for each distinct name. For example, even though methamphetamine, methedrine and desoxyn are the same drug, their use was measured in three separate variables.

This series measures the prevalence and correlates of drug use in the United States. The surveys are designed to provide quarterly, as well as annual, estimates. Information is provided on the use of illicit drugs, alcohol, anabolic steroids, and tobacco among members of United States households aged 12 and older. Questions include age at first use, as well as lifetime, annual, and past-month usage for the following drug classes: marijuana, inhalants, cocaine, hallucinogens, heroin, alcohol, tobacco, and nonmedical use of psychotherapeutics. Respondents were also asked about problems resulting from their use of drugs, alcohol, and tobacco, their perceptions of the risks involved, insurance coverage, and personal and family income sources and amounts. Demographic data include gender, race, ethnicity, educational level, job status, income level, household composition, and population density.

ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection: Performed consistency checks.; Standardized missing values.; Created online analysis version with question text.; Checked for undocumented or out-of-range codes..

Multistage area sample design with an oversampling of young people, minorities, and the Washington, DC, Metropolitan Statistical Area.

The population of the continuous United States, aged 12 and older, living in households.

Datasets: DS1: National Household Survey on Drug Abuse (NHSDA), 1990

National Survey on Drug Use and Health (NSDUH) Series