Using the Site
- Overview
- Searching and Finding the Data You Need
- Accessing Data
- Downloading Data
- Analyzing Data Using Statistical Software
- Online Data Analysis Using SDA
- Producing Quick Tables
- Using the Interactive Maps
Overview
SAMHDA is an initiative of the Center for Behavioral Health Statistics and Quality (CBHSQ, formerly the Office of Applied Studies) 
,
Substance Abuse and Mental Health Services Administration (SAMHSA) of
the United States Department of Health and Human Services . The goal of
the archive is to provide access to substance abuse and mental health research data. SAMHDA provides data to study substance abuse and mental health problems. SAMHDA holdings consist mainly of data derived from surveys and administrative records. SAMHDA preserves these data and makes them publicly available for
secondary analysis. The public-use
files in the SAMHDA holdings may not always match the original research data because variables
that pose a risk may be modified or removed from the data file.
SAMHDA allows users to download the data set(s) to a personal computer for analysis using their own statistical software. Users can also view or download all available documentation files for the study. In addition, many studies are available to users for online analyses using the online Survey Documentation and Analysis system (SDA). Some SAMHDA studies have an available feature called Quick Tables, which allows users to produce tables by choosing from pre-selected variables available in drop-down menus. Another way to explore data is through Interactive Maps, which allows users to explore data geographically. You will need basic statistical skills for using SDA, Quick Tables, or Interactive Maps. You can view findings that others have published based on SAMHDA data by selecting the Related Literature link on any given study home page.
Searching and Finding the Data You Need
One way to explore datasets on the SAMHDA site is to use the Newest Series section on the home page. The studies listed in the Newest Series section are the newest and/or most used studies in the SAMHDA archive. Selecting one of these studies will take you to the home page for that study.
Another way to locate a particular study archived by SAMHDA is to Browse All Studies. This feature provides a listing of all holdings with links to the study home page. From a study home page, you may choose to:
- read a brief summary of the study
- view the study description
- browse complete study documentation (codebooks, questionnaires)
- list all variables in the study
- perform a variable level search within the study
- view related literature
- view related literature for the entire series (if part of a series)
- download documentation files
- download select data files
- analyze data online -- SDA, Quick Tables, Interactive Maps (when available)
One more way to find studies or variables of interest is to use the search box that appears at the top of each SAMHDA page. There are three search options:
- The Variables option searches question text, value labels, and variable labels for every variable in all the studies. This is the default setting for the search utility.
- The Study Descriptions option searches for keywords or phrases within studies' metadata.
- The Publication option searches the database of publications based on SAMHDA data.
When performing a Variables search, the results page will list the studies, sorted in descending order, by the number of variables found within that study that match the search term. There are three options to select from:
- a list of the matching variables for that study;
- the study home page; or
- a list of all the variables for that particular study.
Another option available is to see a list of all of the matching variables located at the top of the results page just above the list of studies. From this new results page you will be able to utilize our faceted searching to narrow your results by series, study, or time period. Once you select a variable from the list of matching results, you will be able to view key information about the variable including: name, label, question text, frequencies, and summary statistics. From this page, you will have the ability to conduct a secondary search for other variables within the study you originally selected, view all of the variables within the study, view the entire SDA codebook, and go to the study home page.
The second type of search that you can conduct is a Study Descriptions search. This will return a list of studies that contain your search word(s) somewhere in the study description, study documentation, publication citations, as well as the variable name, question text, value labels, or variable labels. From the results page you can go directly to the study home page. On the right side of the screen you will notice several different options for filtering results. For more detailed examples of using these filters, consult the FAQ on faceted searching.
For additional information on finding data, we encourage you to consult our FAQ section on How to Find Data.
Accessing Data
Data in the SAMHDA archive are freely available. Therefore, users do not need to obtain permission to access, analyze, or publish findings based on SAMHDA data; however, all users of SAMHDA data must abide by the Terms of Use and properly cite the data files.
Downloading Data
From the study home page you have the option to download the documentation files, download data files for a selected statistical program, or download all of the data and documentation files.
If you are uncertain whether a study fits your needs, we recommend selecting the "Browse documentation files" option on the study home page. This will allow you to view codebooks, questionnaires (if present), and any other study documentation available for the selected study. You can also download the documentation files. You will be required to agree to the Terms of Use prior to downloading any data.
On the download page, you have the option of downloading the data into either a system file or an ASCII data file with an accompanying setup file. With either option you can download the data in SAS, SPSS, Stata, or another format (see the note on the right about what might be contained in the Other Data column). You also have the option to download all of the files (both system and ASCII plus setup files for all three statistical packages).
For additional information on downloading data, we encourage you to consult the FAQ section on How to Download Data.
Analyzing Data Using Statistical Software
SAMHDA currently provides software-specific data files for three of the more commonly used analytical software packages for the social sciences: SAS (transport files), SPSS (portable or system files), and Stata (system files). There are also SAS and Stata supplemental syntax files, which are used to apply values labels (SAS) or to apply the missing value recodes (SAS and Stata). All SAMHDA studies include ASCII data files and setup files, which allow the user to read ASCII data files into statistical software packages. SAMHDA currently provides setup files for SAS, SPSS, and Stata. Additionally, most SAMHDA studies have a tab-delimited file available. This file type is most commonly used in conjunction with Microsoft Excel.
SAS, SPSS, and Stata setup files and software-specific data files can be used either with the procedural version of these packages or with their Windows counterpart. The following instructions explain the different components of SAS, SPSS, and Stata setup files. Setup files for certain collections may not contain all of the commands in the examples given below.
- Examples of Setup Files
- How to Use Setup Files to Read ASCII Data
Online Data Analysis Using SDA
SAMHDA provides an online
data analysis system, Survey Documentation and Analysis (SDA)
. SDA was developed and is maintained by the
Computer-assisted Survey Methods Program (CSM) at the University of California, Berkeley. Almost all SAMHDA
data collections are available for online data analysis. SDA allows users to explore the data without having to download data files or setup files, and without requiring familiarity
with any statistical package. Users may create custom subsets of cases and/or variables and download the subsets
to their computers. This option can be used when the data file is very large.
SAMHDA provides several resources to help users learn and use SDA. The
SDA Tutorial is a resource that provides a guided interactive tour of some of the most commonly used features of SDA. Another useful resource
is CSM's Online Help Files for SDA Users .
Also, many of the analytical terms and options within SDA have clickable links that produce online help
documentation. ICPSR provides video tutorials on
select SDA topics .
A final help resource is the FAQ section of Analyze Data Online With SDA.
Most of SAMHDA's holdings are available for online analysis using SDA. Currently, the National Youth Survey series (NYS), Drug Services Research Survey (DSRS) study and Services Research Outcomes Study (SROS) cannot be used with SDA; however, they still have SDA codebooks available. In some cases, only one part of a study is available (e.g., Alcohol and Drug Services Study (ADSS), Monitoring the Future (MTF)). SAMHDA also concatenates some studies, merging each part into a single SDA file (e.g., Drug Abuse Treatment Outcome Study (DATOS), Drug Abuse Treatment Outcome Study-Adolescent (DATOS-A), National Comorbidity Survey: Baseline (NCS-1), National Treatment Improvement Evaluation Study (NTIES)).
There are three ways to access SDA:
- The Analyze Data Online link from the tool bar on the left side of every SAMHDA Web page leads to drop-down selection menus for all studies for which the SDA analysis feature is available.
- The series home page contains a drop-down menu for studies or study parts available in SDA.
- The study home page contains a link to analyze data using SDA. A "Quick SDA" button is also available on the top-right of the home page for studies containing a single part or studies with only one part available on SDA. For those studies with multiple parts on SDA (e.g., GIBS, NDATSS, PRAMHS), the "Quick SDA" button is not available and you will need to select a part in the Analyze Online drop-down menu.
Producing Quick Tables
Quick Tables are available for selected SAMHDA studies. This feature allows you to produce tables by choosing from among preselected variables available in drop-down menus. Quick Tables are easy to use, but only have a limited number of variables available.
Using the Interactive Maps
Interactive maps allow you to visually explore geographic data using a U.S. map and easy to use drop-down menus. Color-coding enables quick visual identification of a state by category (e.g. percent). More detailed information can be viewed by hovering your mouse over a state of interest. A hyperlink beneath the map allows for tabular display of the data.
Need More Information?
If you have additional questions, please refer to our help documentation, which features several tutorials and a searchable Frequently Asked Questions (FAQ) database. You may contact us if you need further assistance.
