Dietary evaluation and attenuation of relative risk: multiple comparisons between blood and urinary biomarkers, food frequency, and 24-hour recall questionnaires: the DEARR study.
Estimates of diet-disease relative risks (RRs) suffer from inaccuracies introduced by dietary measurement errors. Using the "method of triads," by which the validity coefficient (VC) of the dietary assessment method and "true" long-term intake could be estimated from 3 pairwise correlations between the FFQ, the reference method, and the biomarker, the authors evaluated the performance of a newly developed FFQ. Over a period of 13 mo (September 2000 to September 2001), 161 participants completed 3 FFQs and six 24-h recalls (24HRs), and supplied 2 blood samples and three 24-h urine collections. For protein, beta-carotene, and folic acid, the VCs of the FFQ with the "true intake" (0.77, 0.65, and 0.72, respectively) were relatively higher than the VCs of 24HRs (0.68, 0.60 and 0.39, respectively). Among the biomarkers, the VCs of serum beta-carotene and folic acid with the "true intake" (0.65 and 0.65) were higher than the VCs of urinary nitrogen and alpha-tocopherol (0.44 and 0.34, respectively). The DEARR study showed that the newly developed FFQ is a valid and reproducible instrument for assessing dietary intake. The VCs obtained can be used for future adjustment of diet-disease RR estimates in this population.
Shai
Iris
I
Departments of Nutrition and Epidemiology, Harvard School of Public Health, Boston, MA, USA. ishai@hsph.harvard.edu
Rosner
Bernard A
BA
Shahar
Danit R
DR
Vardi
Hilel
H
Azrad
Ayelet B
AB
Kanfi
Ayala
A
Schwarzfuchs
Dan
D
Fraser
Drora
D
D015415:Biomarkers / Q000097:blood* / Q000652:urine*; D004032:Diet; D019587:Dietary Supplements; D002149:Energy Intake; D005247:Feeding Behavior; D005492:Folic Acid / Q000097:blood / Q000652:urine; D006801:Humans; D015203:Reproducibility of Results; D012306:Risk; D011795:Surveys and Questionnaires; D019207:beta Carotene / Q000097:blood / Q000652:urine
D015415:Biomarkers; D019207:beta Carotene; D005492:Folic Acid