Change in methodology for collection of drinking water intake in What We Eat in America/National Health and Nutrition Examination Survey: implications for analysis.

摘要

Objective. To provide updated estimates of drinking water intake (total, tap, plain bottled) for groups aged >=1 year in the USA and to determine whether intakes collected in 2005-2006 using the Automated Multiple-Pass Method for the 24 h recall differ from intakes collected in 2003-2004 via post-recall food-frequency type questions. Design. Cross-sectional, observational study. Setting. What We Eat in America (WWEIA), the dietary intake component of the US National Health and Nutrition Examination Survey (NHANES). Subjects. Individuals aged >=1 year in 2003-2004 (n 8249) and 2005-2006 (n 8437) with one complete 24 h recall. Results. The estimate for the percentage of individuals who reported total drinking water in 2005-2006 was significantly (P < 0.0000) smaller (76.9%) than that for 2003-2004 (87.1%), attributable to a lower percentage reporting tap water (54.1% in 2005-2006 v. 67.0% in 2003-2004; P = 0.0001). Estimates of mean tap water intake differed between the survey cycles for men aged >=71 years. Conclusions. Survey variables must be examined before combining or comparing data from multiple WWEIA/NHANES release cycles. For at least some age/gender groups, drinking water intake data from NHANES cycles prior to 2005-2006 should not be considered comparable to more recent data. Copyright copyright The Authors 2012.