DOI: 10.3886/icpsr34415.v1
title: National Survey on Drug Use and Health: 4-Year R-DAS (2002 to 2005, 2006 to 2009, and 2010 to 2013)
title: Version 1

description: This file includes data from the 2002 through 2013 National Survey on Drug Use and Health (NSDUH) survey. The only variables included in the data file are ones that were collected in a comparable manner across all four years from 2002-2005, from 2006-2009, or from 2010-2013. The National Survey on Drug Use and Health (NSDUH) series (formerly titled National Household Survey on Drug Abuse) primarily 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, and tobacco among members of United States households aged 12 and older. Questions included age at first use as well as lifetime, annual, and past-month usage for the following drug classes: marijuana, cocaine (and crack), hallucinogens, heroin, inhalants, alcohol, tobacco, and nonmedical use of prescription drugs, including pain relievers, tranquilizers, stimulants, and sedatives. The survey covered substance abuse treatment history and perceived need for treatment. The survey included questions concerning treatment for both substance abuse and mental health-related disorders. Respondents were also asked about personal and family income sources and amounts, health care access and coverage, illegal activities and arrest record, problems resulting from the use of drugs, and needle-sharing. Certain questions are asked only of respondents aged 12 to 17. These "youth experiences" items covered a variety of topics, such as neighborhood environment, illegal activities, drug use by friends, social support, extracurricular activities, exposure to substance abuse prevention and education programs, and perceived adult attitudes toward drug use and activities such as school work. Also included are questions on mental health and access to care, perceived risk of using drugs, perceived availability of drugs, driving and personal behavior, and cigar smoking. Demographic information includes gender, race, age, ethnicity, marital status, educational level, job status, veteran status, and current household composition. In the income section, which was interviewer-administered, a split-sample study had been embedded within the 2006 and 2007 surveys to compare a shorter version of the income questions with a longer set of questions that had been used in previous surveys. This shorter version was adopted for the 2008 NSDUH and will be used for future NSDUHs.
description: Only combined 4-year estimates for the years 2002-2005, 2006-2009, and 2010-2013 are possible with the available R-DAS analysis weight. All analyses done within the R-DAS automatically apply the weight variable. Unweighted analyses are not feasible through the R-DAS.
description: 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..
description: Response Rates: Strategies for ensuring high rates of participation resulted in the following rates for each of the following years: 2013 weighted screening response rate of 83.9 percent and a weighted interview response rate for the CAI of 71.7 percent. 2012 weighted screening response rate of 86.1 percent and a weighted interview response rate for the CAI of 73.0 percent. 2011 weighted screening response rate of 87.0 percent and a weighted interview response rate for the CAI of 74.4 percent. 2010 weighted screening response rate of 88.4 percent and a weighted interview response rate for the CAI of 74.6 percent. 2009 weighted screening response rate of 88.4 percent and a weighted interview response rate for the CAI of 75.6 percent. For 2008 the response rates were 88.6 percent and 74.2 percent respectively For 2007 the response rates were 89.1 percent and 73.9 percent respectively For 2006 the response rates were 90.2 percent and 74.2 percent respectively For 2005 the response rates were 91.3 percent and 76.2 percent respectively For 2004 the response rates were 90.9 percent and 77.0 percent respectively For 2003 the response rates were 90.7 percent and 77.4 percent respectively For 2002 the response rates were 90.7 percent and 78.6 percent respectively (The response rates for the 2006-2009 files are based on the revised (March 2012) data files used in this R-DAS.) (Note that these response rates reflect the full analytic sample, not the subsampled data file referenced in this document.)
description: Datasets: 
 
 DS1: National Survey on Drug Use and Health: 4-Year R-DAS (2002 to 2005, 2006 to 2009, and 2010 to 2013)
description: National Survey on Drug Use and Health (NSDUH) Series
description: audio computer-assisted self interview (ACASI), computer-assisted personal interview (CAPI), computer-assisted self interview (CASI) 
Data were collected and processed under contract by Research Triangle Institute, Research Triangle Park, North Carolina.
Since 1999, the survey sample has employed a 50-State design with an independent, multistage area probability sample for each of the 50 States and the District of Columbia.
Prior to the 2002 survey, this series was titled National Household Surveys on Drug Abuse.
Although the design of the 2002 to 2013 surveys is similar to the design of the 1999 through 2001 surveys, there are important methodological differences since 2002 that affect the 2002 to 2013 estimates. Each NSDUH respondent since 2002 has been given an incentive payment of $30. This change resulted in an improvement in the survey response rate. In addition, in 2002 new population data from the 2000 decennial Census became available for use in NSDUH sample weighting procedures. Therefore the data from 2002 and later should not be compared with data collected in 2001 or earlier to assess changes over time.
For selected variables, statistical imputation was performed following logical inference to replace missing responses. These variables are identified in the codebook as "...LOGICALLY ASSIGNED" for the logical procedure, or by the designation "IMPUTATION-REVISED" in the variable label when the statistical procedure was also performed. The names of statistically imputed variables begin with the letters "IR". For each imputation-revised variable, a corresponding imputation indicator variable indicates whether a case's value on the variable resulted from an interview response or was imputed. Missing values for some demographic variables were imputed by the unweighted hot-deck technique used in previous surveys. Beginning in 1999, imputation of missing values for most variables was accomplished using predictive mean neighborhoods (PMN), a new procedure developed specifically for this survey. Both the hot-deck and PMN imputation procedures are described in the codebook.
Since these data are only available in the Restricted-use Data Analysis System (R-DAS), the disclosure protection techniques differ from the downloadable public NSDUH data. For example, a different subsample was drawn for the NSDUH R-DAS files. A selected set of variables that are not available on the NSDUH public-use files, such as the state identifier, are available on the NSDUH R-DAS files.
Previously published estimates may not be exactly reproducible from the variables in the public use file or from the official published estimates due to the disclosure protection procedures that were implemented.
 This file allows the creation of combined 4-year estimates. To generate correct estimates for the NSDUH 4-Year R-DAS data files, users must use the year pair indicator variable (YRPRIND) in one of the following ways: 1. As a filter to subset the data file for a specific group of years such as: "YRPRIND(5)" for 2002-2005, "YRPRIND(6)" for 2006-2009, or "YRPRIND(11)" for 2010-2013 in the filter field. 2. As a control variable. PLEASE NOTE: This option will produce separate results for each combined group of years (e.g., 2002-2005). The last table with total estimates is invalid and should be ignored. 3. As a row variable in the row field. PLEASE NOTE: Under this option the column total estimates are invalid and should be ignored. 4. As a column in the column field. PLEASE NOTE: Under this option the row total estimates are invalid and should be ignored. The NSDUH R-DAS data files do not allow for the creation of single-year estimates because of the potential for disclosure of confidential information. The NSDUH 4-Year R-DAS data files contain revised weights designed to produce estimates that are representative of the average population across combined four-year (2002-2005, 2006-2009, and 2010-2013) periods. There are no weights on the 4-year R-DAS that are representative of all twelve years; thus all estimates of totals across the entire period from 2002-2013 will be three times as large as they should be. To get the correct estimates of totals across the twelve year period, the 12-year R-DAS file should be used.
description: The civilian, noninstitutionalized population of the United States aged 12 and older, including residents of noninstitutional group quarters such as college dormitories, group homes, shelters, rooming houses, and civilians dwelling on military installations.
description: A multistage area probability sample for each of the 50 states and the District of Columbia has been used since 1999. The 2005 NSDUH was the first survey in a coordinated five-year sample design. Although there is no overlap with the 1999-2004 samples, the coordinated design for 2005 through 2009 facilitated a 50 percent overlap in second-stage units (area segments [see below]) between each two successive years from 2005 through 2009. The 2004 NSDUH continued the 50 percent overlap by retaining approximately half of the first-stage sampling units from the 2003 survey. This design was intended to increase precision of estimates in year-to-year trend analyses because of the expected positive correlation resulting from the overlapping sample between successive survey years. The 1999 to 2013 design allows for computation of estimates by state in all 50 states plus the District of Columbia. States may therefore be viewed as the first level of stratification as well as a reporting variable. Eight states, referred to as the large sample states, had a sample designed to yield 3,600 respondents per state for each year of the study. This sample size was considered adequate to support direct state estimates. The remaining 43 states (which include the District of Columbia) had a sample designed to yield 900 respondents per state for each year of the study. In these 43 states, adequate data were available to support reliable state estimates based on SAE methodology. Within each state, sampling strata called state sampling (SS) regions were formed. Based on a composite size measure, states were partitioned geographically into roughly equal-sized regions. In other words, regions were formed such that each area yielded, in expectation, roughly the same number of interviews during each data collection period. The eight large sample states were divided into 48 SS regions each. The remaining states were divided into 12 SS regions each. Therefore, the partitioning of the United States resulted in the formation of a total of 900 SS regions. Unlike the 1999 through 2004 surveys, the first stage of selection for the 2005 through 2013 NSDUHs was Census tracts. The first stage of selection began with the construction of an area sample frame that contained one record for each Census tract in the United States. If necessary, Census tracts were aggregated within SS regions until each tract had, at a minimum, 150 dwelling units in urban areas and 100 dwelling units in rural areas. These Census tracts served as the primary sampling units (PSUs) for the coordinated five-year sample. One area segment (one or more Census blocks) was selected within each sampled Census tract. In advance of the survey period, specially trained listers had visited each area segment and listed all addresses for housing units and eligible group quarters units in a prescribed order. Systematic sampling was used to select the allocated sample of addresses from each segment. To improve the precision of the estimates, the sample allocation process targeted five age groups: 12 to 17 years, 18 to 25 years, 26 to 34 years, 35 to 49 years, and 50 years or older. The size measures used in selecting the area segments were coordinated with the dwelling unit and person selection process so that a nearly self-weighting sample could be achieved in each of the five age groups.