There were potentially six questionnaires a participant could have completed around the time he/she entered the trial: the Baseline Questionnaire, the Supplemental Questionnaire, the Dietary Questionnaire, the Diet History Questionnaire, the Medication Use Questionnaire, and the Brief Survey Questionnaire.
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.