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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

Dietary (DQX)

Timeline from T0 to T13 showing the collection of dietary questionnaires (DQX) in the trial. Only the intervention arm completed the DQX at T0. The control arm was not given the DQX.

The Dietary Questionnaire (DQX) was offered to intervention arm participants around the time they were randomized. 82% of the intervention arm completed a DQX. Control arm participants were not offered the DQX. The form may have been completed before (<1%) or after the participant was randomized, but about half (47%) were collected within one month of randomization and most (90%) were collected within three months.

Raw questionnaire responses were processed into analysis-ready variables in terms of gram intake, pyramid servings, food frequencies per day, etc.

DQX data can be obtained in the DQX dataset.

Summary Available Data
  • Participant-reported data
  • Covers ~61,000 participants
  • Intervention arm only
  • Of collected forms, 98% completed between day of randomization and 8.1 months after randomization
  • Median time into study collected: 0 years
  • Median time post-collection: 13 years
  • Forms used:
  • Form completion details
  • Lifestyle (alcohol use and physical activity)
  • Nutrient intake
  • Supplement intake
  • Glycemic index/load
  • Meat-specific variables
  • Pyramid servings
  • Daily grams of various foods and beverages
  • Daily frequencies of various foods and beverages
  • Raw questionnaire responses