title: Change in methodology for collection of drinking water intake in What We Eat in America/National Health and Nutrition Examination Survey: implications for analysis.
abstract: 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.
  
  
  METHODS
  Cross-sectional, observational study.
  
  
  METHODS
  What We Eat in America (WWEIA), the dietary intake component of the US National Health and Nutrition Examination Survey (NHANES).
  
  
  METHODS
  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.
authors.affiliation: U.S. Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, Food Surveys Research Group, BARC-West, Beltsville, MD 20705-2350, USA. Rhonda.Sebastian@ars.usda.gov
authors.forename: Rhonda S
authors.initials: RS
authors.lastname: Sebastian
authors.forename: Cecilia
authors.initials: C
authors.lastname: Wilkinson Enns
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Goldman
authors.forename: Alanna J
authors.initials: AJ
authors.lastname: Moshfegh
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004032:Diet; D060766:Drinking Water / Q000008:administration & dosage*; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys / Q000379:methods*; D011795:Surveys and Questionnaires; D014481:United States; D055815:Young Adult
chemical_list: D060766:Drinking Water