DOI: 10.3886/icpsr04373.v4
title: National Survey on Drug Use and Health, 2004
title: Version 4

description: The National Survey on Drug Use and Health (NSDUH) series
(formerly titled National Household Survey on Drug Abuse) 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, and included questions from the Diagnostic and Statistical
Manual (DSM) of Mental Disorders that allow diagnostic criteria to be
applied. 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.
Questions introduced in previous administrations were retained in the
2004 survey, including questions 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. Several measures
focused on prevention-related themes in this section. Also retained
were questions on mental health and access to care, perceived risk of
using drugs, perceived availability of drugs, driving and personal
behavior, and cigar smoking. Questions on the tobacco brand used most
often were introduced with the 1999 survey and retained through the
2003 survey. Background information includes gender, race, age,
ethnicity, marital status, educational level, job status, veteran
status, and current household composition. In addition, in 2004 Adult and Adolescent Mental Health modules were added.
description: The "basic sampling weights" are equal to the inverse of the
probabilities of selection of sample respondents. To obtain "final
NSDUH weights," the basic weights were adjusted to take into account
dwelling unit-level and individual-level nonresponse and then further
adjusted to ensure consistency with intercensal population projections
from the United States Bureau of the Census. In the 2004 NSDUH, a
split-sample design for respondents aged 18 or older was implemented.
Thus in 2004, two additional person-level analysis weights other than
ANALWT_C were created. They are SPDWT_C and DEPWT_C. These weights
were created for specific types of person-level analyses. Depending on
the section(s) of the 2004 survey from which the variable(s)
originated, one of the three sampling weights must be selected and
applied. Please refer to the Processor Notes in the codebook for
details on determining the appropriate weight to use when analyzing a
specific variable or combination of variables.
description: Response Rates: The study yielded a weighted screening response rate
of 91 percent and a weighted interview response rate for the Computer
Assisted Interview (CAI) of 77 percent.
description: A multistage area probability sample for each of the 50
states and the District of Columbia was used since 1999. The 2004 sample design
is a continuation of the coordinated five-year sample design that was
implemented for the 1999 through 2003 surveys. Although there is no
overlap with the 1998 sample, the design facilitates overlap in the
first-stage units (area segments) between each two successive years in
the five-year design. The 2004 NSDUH continued the 50 percent overlap
by retaining approximately half of the first-stage sampling units from
the 2003 survey. This design increases the precision of estimates in
year-to-year trend analysis. The sample is stratified on multiple
levels, beginning with states. Eight states are considered large
sample states and contribute approximately 3,600 respondents per
state. The remaining states are sampled to yield 900 respondents per
state. The second level of stratification divides states into Field
Interviewer (FI) Regions. For the first stage of sampling, each FI
region was partitioned into small geographic areas composed of
adjacent Census blocks. These geographic clusters of blocks are
referred to as segments, but were actually the primary sampling units
(PSUs) for the coordinated five-year sample design. 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. Each respondent
who completed a full interview was given a $30 cash payment. Persons
were selected from the address roster using a handheld computer. To
improve the precision of estimates, the sample allocation process
targeted five age groups: 12-17, 18-25, 26-34, 35-49, and 50 and
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. The sample design included approximately equal
numbers of persons in the 12-17, 18-25, and 26 and older age
groups. The achieved sample for the 2004 NSDUH was 67,760 persons. The
public use file contains 55,602 records due to a subsampling step used
in the disclosure protection procedures. Minimum item response
requirements were defined for cases to be retained for weighting and
further analysis (i.e., "usable" cases). These requirements, as well
as full sampling methodology, are detailed in the codebook.
description: Datasets: 
DS1: National Survey on Drug Use and Health, 2004
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: audio computer-assisted self interview (ACASI); computer-assisted personal interview (CAPI)Data were collected and prepared for release by
Research Triangle Institute, Research Triangle Park, North Carolina.Prior to the 2002 survey, this series was titled National
Household Surveys on Drug Abuse.Although the design of the 2004 survey is similar to the design of the 1999 through 2001 surveys, there are important methodological differences since 2002 that affect the 2004 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.To protect the privacy
of respondents, all variables that could be used to identify
individuals have been encrypted or collapsed in the public use
file. To further ensure respondent confidentiality, the data producer
used data substitution and deletion of state identifiers and a
subsample of records in the creation of the public use file.Previously published estimates may not be exactly reproducible from
the variables in the public use file due to the disclosure protection
procedures that were implemented.The data definition and
dictionary files for Stata are designed to be compatible with StataSE,
Version 8. This is a large data file requiring that approximately 250
megabytes of Random Access Memory be allocated to Stata. Operations
within Stata, including conversion of the ASCII data to Stata format,
are likely to be slow. Analysts may wish to download subsets of data
from the SAMHDA Data Analysis System (DAS) for use with Stata.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.