To the Editor.
—While it is attractive in these high-tech times to embrace low-tech approaches to disease prevention and control, Dr Avorn and colleagues1 have not made their case for cranberry juice. From data in Table 1 of the article (page 753), it is apparent that their randomization and/or blinding scheme failed and that the two groups were not comparable with regard to previous UTI (Table). Analysis of the history of UTI for the prior 6-month and 12-month periods demonstrates a significant excess in the placebo group during both periods (P=.004, odds ratio [OR]=4.39, 95% confidence interval 1.55 to 12.43, using the approximation of Woolf, and P=.03, OR=2.50, 95% confidence interval 1.15 to 5.42, using the approximation of Woolf, respectively [Fisher's exact test]), suggesting the placebo group was more likely at baseline to experience UTI or bacteriuria/pyuria than the treatment group.
Katz LM. Reduction of Bacteriuria and Pyuria Using Cranberry Juice. JAMA. 1994;272(8):589. doi:10.1001/jama.1994.03520080030024