mental health services,
substance abuse treatment,
Date of Collection:
Unit of Observation:
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.
Data Collection Notes:
Data were collected and prepared for release by
Research Triangle Institute, Research Triangle Park, NC.
National Household Survey on Drug Abuse questionnaire and estimation
methodology changed with the implementation of the 1994-B
survey. Therefore, estimates produced from the 1997 survey are not
comparable to those produced from the 1994-A and earlier surveys.
For selected variables, statistical imputation was performed following
logical imputation to replace missing responses. These variables are
identified in the codebook as "...LOGICALLY IMPUTED" and
"...imputed" 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 there is a corresponding imputation indicator variable that
indicates whether a case's value on the variable resulted from an
interview response or was imputed by the hot-deck technique. Hot-deck
imputation is described in the codebook.
The "basic sampling
weights" are equal to the inverse of the probabilities of selection
of sample respondents. To obtain "final NHSDA 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.
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. These
modifications should not affect analytic uses of the public use
Users who wish to replicate results published in the NHSDA
Main Findings Report or other SAMHSA reports should use the 1997 NHSDA
imputed data for prevalence estimates rather than raw data from the
questionnaire or drug answer sheets.
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.
Multistage area probability sample design involving five
selection stages: (1) primary sampling unit (PSU) areas (e.g., counties), (2) subareas within primary areas (e.g., blocks or block groups), (3) listing units within subareas, (4) age domains within sampled listing units, and (5) eligible individuals within sampled age domains. The 1997 NHSDA used the same 115 PSUs as the 1995 and 1996 NHSDAs, plus a total of 18 supplemental PSUs from Arizona and
California. The 115 PSUs were selected to represent the nation's total eligible population, including areas of high Hispanic concentration. These PSUs were defined as metropolitan areas, counties, groups of counties, Census tracts, and independent cities. Of the 115 PSUs, 43 were selected with certainty and 72 were randomly selected with
probability proportional to size (PPS). The national sample was supplemented by a PPS selection of 14 noncertainty PSUs from Arizona plus 4 noncertainty PSUs from California. Because the national sample provided representation for certainty PSUs in each state, no additional certainty PSUs were added to either sample. Unlike NHSDAs prior to 1996, the 1996 and 1997 NHSDAs did not oversample cigarette
smokers aged 18-34. Unlike the 1996 NHSDA, which reused about 95 percent of the sample segments used in 1995, the 1997 NHSDA basically surveyed a new segment sample. Only 96 segments in the 1997 NHSDA overlapped with 1996 segments. Beginning in quarter two of the 1997 NHSDA, residents of Arizona and California were oversampled to provide
direct survey estimates for these states. Due to confidentiality concerns, there is no variable on the public use data file to indicate a state identifier. The five age groups were: ages 12-17, 18-25, 26-34, 35-49, and 50 and older. The three race/ethnic groups were: Whites/others, non-Hispanic Blacks, and Hispanics. Blacks and Hispanics were oversampled. The study yielded an 85.0 percent
eligibility rate for sample households and a 92.7 percent completion rate for screening eligible households.
Data were weighted based on the
five stages of sampling that were used. 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. The final weight variable to be used in analysis is ANALWT.
personal interviews and self-enumerated answer sheets
The interview response rates for the three racial/ethnic groups were: 75.5 percent for Whites/others, 81.8
percent for Blacks, and 82.5 percent for Hispanics. The overall unweighted interview response rate was 78.3 percent. A completed interview had to contain, at a minimum, data on the recency of use of marijuana, cocaine, and alcohol.
Extent of Processing: 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.
Restrictions: Users are reminded by the United States Department of Health and Human Services that these data are to be used solely for statistical analysis and reporting of aggregated information and not for the investigation of specific individuals or treatment facilities.