CDHA is developing expertise in computer security and data confidentiality, electronic archiving, and remote computing. CDHA has created the Offline Longitudinal Data Repository (OLDR) to protect the confidentiality and integrity of sensitive administrative, longitudinal, and medical records datafiles. CDHA's remote computing service (WISR) provides a secure computing environment for researchers conducting analysis of sensitive data archived with OLDR. CDHA can assist researchers to create, document, and distribute public use microdata for secondary analysis. Non-sensitive public use data archived with CDHA are currently published to the CDE/CDHA FTP site, and CDHA is experimenting with software for publishing data and associated documentation that meets archival standards to the web. Assistance in developing customized security and confidentiality protocols for IRB review or Certificates of Confidentiality is available as is assistance in obtaining a license for restricted data traditionally housed at other institutions including the other NIA demography centers.

Secure Data Archiving

Any information that could be used to directly or indirectly identify a survey respondent or research subject and information that might be damaging to an individual's financial standing, employability, or reputation within the community or could reasonably lead to social stigmatization or discrimination is considered sensitive as is information concerning sexual attitudes, preferences, or practices; alcohol, drug, or other additive product use; illegal conduct; psychological wellbeing or mental health. Researchers who use or generate sensitive data on health and aging may archive these data with CDHA's Offline Longitudinal Data Repository (OLDR). Archiving with OLDR protects respondent confidentiality and data integrity, provides long-term usability of electronic data in the face of changing computer technology, promotes the development of longitudinal databases in health and aging by providing a secure archive for subject identifiers (e.g., name, phone number, address), and provides a secure environment in which to link sensitive survey and administrative data. Data and associated documentation deposited with OLDR is reviewed to ensure accuracy and integrity, so the secondary users of these data are assured of its quality. Documentation submitted to CDHA by researchers archiving with OLDR is used to create metadata (i.e., a description of the data adequate for cataloging materials and facilitating secondary analysis), to acquire legal protection for identifying or sensitive information from subpoena, and to create a data access protocol defining the conditions for data access. CDHA assumes the responsibility for creation and maintenance of a master and backup copy of all archived data and annually samples these copies in order to detect any degradation of the data or media. Sensitive data are encrypted and stored in a secure offsite location. Data are migrated to new media as required by changing computer hardware and storage technology in order to maintain long-term usability.

Data Access

In order to maximize the long-term benefits of current research funding, CDHA assists researchers to create data documentation that meets archival standards established by the Data Documentation Initiative (DDI) and helps researchers generating sensitive data to create public use microdata. Public use data archived with CDHA will be published to the CDHA website. Sensitive data, on the other hand, are stored on the secure archive (OLDR) and are physically accessible only to CDHA's Data Analyst/Archivist. Researchers gain access to the sensitive data stored on the secure archive by submitting digitally signed authenticated code. Statistical analysis generated by the researcher's code is reviewed for potential identity disclosure and, if the statistical output does not appear to breach confidentiality, it is given to the researcher. If the analysis would make it possible to identify individual subjects, then the Data Analyst/Archivist works with the researcher to protect confidentiality while maintaining the usefulness of the analysis in achieving research objectives.

Download WLS public-use microdata

Download NSFH public-use microdata

Browse an annotated description of selected data resources

Sending SAS or STATA Code to WISR

Home | Data | Projects | Publications | Events | About | Search

Please send questions, comments or suggestions to cdha@ssc.wisc.edu

If you have difficulty accessing this page or have other questions or comments about the webpage please contact cdhadata@ssc.wisc.edu