How to Search Effectively
- You can search by keyword
retirement, "health insurance"or by entering a research question
How many teens smoke marijuana?
- Use quotes for phrase searches; use the minus sign to remove items from results:
"election data" -"opinion poll"
- A Boolean "and" is inferred for multiple search terms.
- Stemming is automatic; do not use an asterisk.
- Search is not case-sensitive.
- You can still search by study number.
Most datasets in NAHDAP are primary data collected from surveys and interviews or obtained from administrative databases. NAHDAP preserves and disseminates them because they have value for "secondary analysis" - that is, reexamining existing data to reproduce original findings, address new questions, or employ new analytic methods.
Browse for Data
- View all studies
- Browse recent updates & additions (last 90 days)
- View all studies for which online analysis is available
- View all studies funded by the National Institute on Drug Abuse
- Browse by subject
You can search over 500,000 variables from NAHDAP studies and construct side-by-side comparisons of up to five variables at a time.
Access to Data
Since NAHDAP is sponsored by the National Institute on Drug Abuse (NIDA), a federal agency, users obtain data from NAHDAP at no charge. To access data files, users must login to ICPSR with an ICPSR MyData account or an existing Google or Facebook account.
Please note that approximately 25% of NAHDAP's studies contain confidential data and are not available for Web download. Instructions on how to obtain those datasets are provided atop the study home page under "Access Notes." You will be required to obtain Institutional Review Board (IRB) approval for your project.
For more information about accessing restricted-use data, see Instructions for Access to Restricted-Use Data.
ICPSR Member-Only Data
Some data listed on the NAHDAP Web site are available only to persons at ICPSR member institutions.
In almost all cases, documentation files, such as codebooks, questionnaires, and user guides, are freely available and do not require authentication.
Additional Data Resources
- HRSA Data and Statistics
- Making CDC Data Interactive
- National Highway Traffic Safety Administration: National Center for Statistics and Analysis (NCSA)
- NIDA Data Harmonization Projects
- PhenX Toolkit
- UNAIDS: Data and Analysis
Free Statistical Software
- Free Statistical Software from Free Statistics
- Free Statistical Software from Statpages.net
- Freeware and Student Versions of Software from the University of Texas
- GraphPad Software -- QuickCalcs
- IVEware Software
- MiniTab Statistical Software
- R Software
- Software from the StatLib at Carnegie Mellon
- Statistics Calculator Links from UCLA