title: Water for preventing urinary calculi.
abstract: BACKGROUND
  Urinary calculi is a common condition characterized of high incidence and high recurrence rate. For a long time, increased water intake has been the main preventive measure for the disease and its recurrence.
  
  
  OBJECTIVE
  To access the effectiveness of increased water intake for the primary and secondary prevention of urinary calculi.
  
  
  METHODS
  Relevant RCTs were identified by electronic and documental searches of MEDLINE, EMBASE, the Chinese Biomedical Disk and the Cochrane Central Register of Controlled Trials. No language restriction was applied. Date of last search: May 2004.
  
  
  METHODS
  Randomised controlled trials (RCTs) and quasi-RCTs of increased water intake for the prevention of urinary calculi and its recurrence.
  
  
  METHODS
  Two reviewers independently assessed trial quality and extracted data. Statistical analyses were performed using the random effects model and the results expressed as relative risk (RR) for dichotomous outcomes or weight mean difference (WMD) for continuous data with 95% confidence intervals (CI).
  
  
  RESULTS
  No trials of increased water intake for the primary prevention of urinary calculi met the inclusion criteria. One trial with 199 patients provided results of increased water intake for the recurrence of urinary calculi. The recurrence rate was lower in the increased water intake group than that of the no intervention group (12% versus 27%, P = 0.008, RR = 0.45, 95% CI 0.24 to 0.84). The average interval for recurrences was 3.23 +/-1.1 years in increased water intake group and 2.09 +/- 1.37 years in the no intervention group (P = 0.016, WMD = 1.14, 95% CI 0.33 to 1.95).
  
  
  CONCLUSIONS
  The evidence from only one trial indicates that increased water intake reduces the risk of recurrence of urinary calculi and prolongs the average interval for recurrences. However further research is required. Due to the lack of appropriate RCTs, no conclusions can be drawn on increased water intake for the primary and secondary prevention of urinary calculi.
authors.forename: W
authors.initials: W
authors.lastname: Qiang
authors.forename: Z
authors.initials: Z
authors.lastname: Ke
mesh_terms: D004326:Drinking; D005440:Fluid Therapy; D006801:Humans; D055502:Secondary Prevention; D014545:Urinary Calculi / Q000517:prevention & control*