title: [Multilevel model analysis on the relevant factors influencing the total amount of drinking water consumed daily by Beijing residents].
abstract: OBJECTIVE
  To investigate the influencing factors for daily water intake of Beijing residents.
  
  
  METHODS
  A multi-stage sampling method was constructed to interview 270 Beijing residents in the winter of 2009 and in the summer of 2010 by using a questionnaire to collect data on daily drinking water consumption. Multilevel models were used to analyze the variation and influencing factors for the amount of water intake.
  
  
  RESULTS
  Multilevel model results showed that the average daily water intake of residents living in different villages or neighborhood committees was statistically significant (sigma2 mu0 = = 0.030 (0.009), P < 0.05). The individual variation in the same village or neighborhood committee was also significant (sigma2 e0 = 0.157 (0.010), P < 0.05). Season, gender, and body weight affected the daily water intake (P < 0.05). There were interaction between season and source of water supply.
  
  
  CONCLUSIONS
  The average daily water intake of residents was affected by several factors. In the health risk assessment of drinking water, it needs considering not only the individual characteristics but also the differences of villages/neighborhood committees and the seasonal variation.
authors.affiliation: Beijing Center for Disease Control and Prevention, Beijing 100013, China. jinhuizhao@sina.com
authors.forename: Jinhui
authors.initials: J
authors.lastname: Zhao
authors.forename: Jianrong
authors.initials: J
authors.lastname: Wei
authors.forename: Huajie
authors.initials: H
authors.lastname: Chen
authors.forename: Yumin
authors.initials: Y
authors.lastname: Liu
authors.forename: Tiantian
authors.initials: T
authors.lastname: Li
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Sun
authors.forename: Qiaolan
authors.initials: Q
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D002681:China; D004326:Drinking; D060766:Drinking Water / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055361:Multilevel Analysis; D012494:Sampling Studies; D011795:Surveys and Questionnaires
chemical_list: D060766:Drinking Water