Cranberry juice for the prevention of recurrences of urinary tract infections in children: a randomized placebo-controlled trial.

BACKGROUND Cranberry juice prevents recurrences of urinary tract infections (UTIs) in adult women. The objective of this study was to evaluate whether cranberry juice is effective in preventing UTI recurrences in children. METHODS A double-blind randomized placebo-controlled trial was performed in 7 hospitals in Finland. A total of 263 children treated for UTI were randomized to receive either cranberry juice (n = 129) or placebo (n = 134) for 6 months. Eight children were omitted because of protocol violations, leaving 255 children for the final analyses. The children were monitored for 1 year, and their recurrent UTIs were recorded. RESULTS Twenty children (16%) in the cranberry group and 28 (22%) in the placebo group had at least 1 recurrent UTI (difference, -6%; 95% confidence interval [CI], -16 to 4%; P = .21). There were no differences in timing between these first recurrences (P = .32). Episodes of UTI totaled 27 and 47 in the cranberry and placebo groups, respectively, and the UTI incidence density per person-year at risk was 0.16 episodes lower in the cranberry group (95% CI, -.31 to -.01; P = .035). The children in the cranberry group had significantly fewer days on antimicrobials (-6 days per patient-year; 95% CI, -7 to -5; P < .001). CONCLUSIONS The intervention did not significantly reduce the number of children who experienced a recurrence of UTI, but it was effective in reducing the actual number of recurrences and related antimicrobial use.