How can I obtain restricted HMCA Data?

Each HMCA data collection has been examined to ensure the confidentiality of research subjects. Variables that pose a disclosure risk are restricted from general dissemination. Restricted variables are removed from the public-use datasets available on our Web site or are modified in a way that limits disclosure. For example, a variable that gives respondents' ages in single years may be recoded to five-year age groups and topcoded at 75 so that age 16 becomes age 15-19 and age 92 becomes 75+.

To obtain restricted variables in their original form, analysts must agree to the terms and conditions of a restricted data use agreement. These legally binding agreements place strict controls on who may access restricted data and how the data are used, stored, and conveyed.

If HMCA has restricted one or more variables in a data collection, that will be noted in the "Restrictions" section of the study description and the "ICPSR Processing Note" in the collection's codebook. The latter may be omitted if the study description or other section of the codebook provides sufficient information on how the restricted variables were handled.