Skip to Main Content

An official website of the United States government


Participants Years enrollment close-out today
Baseline Questionnaire (BQ) ~154,000 1993-2001
Dietary Questionnaire I-only (DQX) ~63,000 1993-2001
Diet History Questionnaire (DHQ) ~119,000 1998-2004
Supplemental Questionnaire (SQX) ~104,000 2006-2007
Medical Use Questionnaire (MUQ) ~60,000 2013
Brief Survey (BCQ) ~47,000 2017-2018
Collection of Cancers
Collection of Mortality

Baseline (BQ)

The Baseline Questionnaire (BQ) is the baseline risk factor questionnaire and contains participant-reported information such as demographics and medical history. The form was offered to all participants, and 96.8% were completed and collected. Compliance was slightly higher in the intervention arm (97.6%) than in the control arm (96.0%). The form may have been completed before or after the participant was randomized, but most (81%) were collected within one month of randomization and nearly all (96%) were collected within three months.

Baseline Questionnaire data and documentation are incorporated into each of the cancer datasets.

Summary Available Data
  • Participant-reported data
  • Covers ~150,000 participants
  • Of collected forms, 98% completed between 2.3 months prior and 5.3 months after randomization
  • Median time into study collected: 0 years
  • Median time remaining after collection: 13 years
  • Forms used:
  • Form completion details
  • Demographics
  • Smoking history
  • Family history of cancer
  • Height, weight and BMI
  • NSAIDS
  • Medical conditions & history of disease
  • Personal history of cancer
  • Female-specific information
  • Male-specific information
  • Screening prior to baseline