Location: Food Surveys Research GroupTitle: Pooled results from five validation studies of dietary self-report instruments using recovery biomarkers for potassium and sodium intake Author
|Freedman, Laurence - The Sheba Medical Center At Tel Hashomer|
|Commins, John - Information Management Services, Inc|
|Moler, James - Information Management Services, Inc|
|Willett, Walter - Harvard School Of Public Health|
|Tinker, Lesley - Fred Hutchinson Cancer Research Center|
|Subar, Amy - National Cancer Institute (NCI, NIH)|
|Spiegelman, Donna - Harvard School Of Public Health|
|Potischman, Nancy - National Cancer Institute (NCI, NIH)|
|Neuhouser, Marian - Fred Hutchinson Cancer Research Center|
|Kipnis, Victor - National Cancer Institute (NCI, NIH)|
|Arab, Lenore - Geffen School Of Medicine|
|Prentice, Ross - Fred Hutchinson Cancer Research Center|
Submitted to: American Journal of Epidemiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/20/2014
Publication Date: 3/18/2015
Citation: Freedman, L.S., Commins, J.M., Moler, J.E., Willett, W., Tinker, L.F., Subar, A.F., Spiegelman, D., Rhodes, D.G., Potischman, N., Neuhouser, M.L., Moshfegh, A.J., Kipnis, V., Arab, L., Prentice, R.L. 2015. Pooled results from five validation studies of dietary self-report instruments using recovery biomarkers for potassium and sodium intake. American Journal of Epidemiology. 181(7)473-487. DOI: 10.1093/aje/kwu325.
Interpretive Summary: Low potassium and sodium intakes have been associated with elevated blood pressure. Studies of dietary intake and their relation to health outcomes often use self-reported intakes; however, reporting error, daily variation in diet, and limitations of food composition databases can affect results. Dietary recovery biomarkers can provide accurate assessments of short term intakes. Results from five large validation studies with biomarkers were pooled for common analysis in order to better describe the nature and magnitude of reporting errors in food frequency questionnaires and 24-hour recalls. Self-reports of dietary intake capture potassium intake quite well but sodium intake is captured less accurately. The sodium-potassium ratio is measured much better than sodium on both food frequency questionnaires and 24-hour recalls.
Technical Abstract: We have pooled data from five large validation studies of dietary self-report instruments that used recovery biomarkers as referents to assess food frequency questionnaires (FFQs) and 24-hour recalls. We reported on total potassium and sodium intakes, their densities, and their ratio. Results were similar across gender, but there was heterogeneity across studies. Average correlation coefficients of reported versus true intake for the FFQs for potassium, potassium density, sodium, sodium density, and sodium-potassium ratio were 0.37, 0.47, 0.16, 0.32, and 0.49, respectively. For the same nutrients with a single 24-hour recall, they were 0.47, 0.46, 0.32, 0.31, and 0.46, respectively, rising to 0.56, 0.53, 0.41, 0.38, and 0.60 for an average of three 24-hour recalls. Average underreporting was 5-6% with a FFQ and 0-4% with a single 24-hour recall for potassium, but 28-39% and 4-13%, respectively, for sodium. Higher BMI was related to underreporting of sodium. Calibration equations for true intake that included personal characteristics provided improved prediction except for sodium density. In summary, self-reports capture potassium intake quite well but sodium intake less well. Using densities improves the measurement of potassium and sodium on a FFQ. The sodium-potassium ratio is measured much better than sodium on both FFQs and 24-hour recalls.