Soft drink consumption and urinary stone recurrence in men
ACP J Club. 1993 May-June;118:94. doi:10.7326/ACPJC-1993-118-3-094b
To the Editor
In a recent issue of ACP Journal Club, our trial (1) was criticized by the commentator (2) for failing to account for the possibility of an important confounding factor, namely urologist co-intervention. The trial results showed abstinence from soft drink consumption was beneficial in reducing urinary stone recurrences in adult men. To invalidate these results, one would have to speculate that co-intervention was applied nonrandomly to the 2 arms. Urologists in the study were blinded to the intervention, all data were collected by the central office directly from the patients, and participants entered the study after the conclusion of their stone episode. Therefore, patients had virtually no further contact with the urologist, and a nonrandom distribution of such co-intervention is extremely unlikely.
Jonathan J. Shuster, PhD
Pediatric Oncology Group
2. Churchill DN. Commentary on "Reduced soft drink consumption led to a reduced risk for urinary stone recurrence in men." ACP J Club. 1993 Jan-Feb:15 (Ann Intern Med. vol 118, suppl 1). Comment on: Shuster J, Jenkins A, Logan C, et al. Soft drink consumption and urinary stone recurrence: a randomized prevention trial. J Clin Epidemiol. 1992;45:911-6.