Water for preventing urinary stones.

backgroundUrinary stones are a common condition characterised by 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. This is an update of a review originally published in 2004.

objectivesTo assess the effectiveness of increased water intake for the primary and secondary prevention of urinary stones. SEARCH

methodsWe searched the Cochrane Renal Group's specialised register, CENTRAL, MEDLINE, EMBASE, and the Chinese Biomedical Disk using a search strategy developed in conjunction with Cochrane Renal Group's Trials Search Co-ordinator. No language restriction was applied. Date of last search: April 2012. SELECTION CRITERIA: Randomised controlled trials (RCTs) and quasi-RCTs of increased water intake for the prevention of urinary stones and its recurrence were included. DATA COLLECTION AND ANALYSIS: Two authors independently assessed risk of bias and extracted data. Statistical analyses were performed using the random effects model and the results expressed as risk ratio (RR) for dichotomous outcomes or mean difference (MD) for continuous data with 95% confidence intervals (CI). MAIN

resultsNo studies of increased water intake for the primary prevention of urinary stones met the inclusion criteria. One study with 199 patients provided results of increased water intake for the recurrence of urinary stones. The stone recurrence was lower in the increased water intake group than that of the no intervention group (12% versus 27%; RR 0.45, 95% CI 0.24 to 0.84). The average interval for recurrence was 3.23 ± 1.1 years in increased water intake group and 2.09 ± 1.37 years in the no intervention group (MD 1.14, 95% CI 0.33 to 1.95). There were insufficient data to assess selection, performance, detection or attrition bias. AUTHORS'

conclusionsThe evidence from only one study indicates that increased water intake reduces the risk of recurrence of urinary stones 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 stones.