Validation of the American Cancer Society Cancer Prevention Study II Nutrition Survey Cohort Food Frequency Questionnaire

We assessed the validity and reproducibility of a self-administered 68-item food frequency questionnaire completed in 1992-1993 by approximately 185,0 00 adults. Four hundred forty-one participants completed four 24-hour dieta ry recall interviews over a 1-year period and a repeat administration of th e food frequency questionnaire. For 20 nutrients and 10 food groups, measur ed nutrient intakes, but not food group intakes, were consistently lower by food frequency questionnaire than by recall. Energy-adjusted, attenuation- corrected Pearson validity correlations ranged from 0.12 to 0.80, with a me dian of 0.58. Reproducibility measures were generally high, with a median o f 0.69. Thr food frequency questionnaire performed similarly to food freque ncy questionnaires used in other cohort studies, indicating similar ability to examine diet disease relations.