Data Curation Questions

Participants can select on a survey-by-survey basis whether to complete surveys in English or Spanish. The CDR does not currently include whether a participant completed a survey in English or Spanish.

To ensure participant privacy, some data are subject to suppression (withholding or removing selected information) or generalization based on re-identification risk.

Registered Tier data include participant-level data with added transformations, which includes date shifts. All dates in the Registered Tier are shifted backwards by a random number between 1 - 365. The shift is constant for each participant so that temporality of events is preserved.

In the Controlled Tier, real (unshifted) dates of events will be available with the exception of date of birth, which is generalized to year of birth.

Read the participant privacy protections for additional information about data included in the Registered Tier and Controlled Tier.

Each CDR includes a date which denotes the cutoff date for data curated and included in a specific CDR. For current and past CDR cutoff and release dates, refer to the Data Dictionaries.

New versions of the Curated Data Repository (CDR) occur on average once a year. For current and past CDR cutoff and release dates, refer to the Data Dictionaries.

Data in the CDR are curated in compliance with our data curation process. For additional information including the data curation process for each data type, read about our data curation process.