AbstractObjectiveTo 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.DesignCross-sectional, observational study.SettingWhat We Eat in America (WWEIA), the dietary intake component of the US National Health and Nutrition Examination Survey (NHANES).SubjectsIndividuals aged ≥1 year in 2003–2004 (n 8249) and 2005–2006 (n 8437) with one complete 24 h recall.ResultsThe 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.ConclusionsSurvey 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.
Change in methodology for collection of drinking water intake in What We Eat in America/National Health and Nutrition Examination Survey: implications for analysis
