Did water fail, or did the coaching? A commentary on the PUSH kidney stone trial
The PUSH trial paid, coached and texted people with kidney stones to drink more, and stone events didn't fall. A Kidney International commentary argues the trial tested a behavioral strategy, not water: urine volume barely separated between the groups.
🎧 Listen: Weekly · Oct 26, from 12:35.
The trial
PUSH, published in The Lancet, randomized 1,658 people aged 12 and older with a history of kidney stones and low urine volume, at six US academic centers, to a multicomponent program (a fluid prescription, financial incentives, health coaching and tools such as text reminders) or guideline-concordant usual care. Over about two years, symptomatic stone events occurred in 154 participants (19%) vs 165 (20%) (hazard ratio 0.96; 95% CI, 0.77 to 1.20). Stone growth and new stones on imaging did not differ. Asymptomatic hyponatremia was more frequent with the program (12 vs 2); no one was hospitalized for it.
The commentary's argument
Drs. Emmanuel Letavernier and Tilman Drüeke argue that PUSH failed as a behavioral strategy, not as a test of water. Median 24-hour urine volumes were 1.81 vs 1.58 L at 6 months and 1.55 vs 1.47 L at 24 months, so by two years the groups were within about a tenth of a liter a day. Controls increased their urine volume too, which was ethically appropriate but shrank the contrast. In contrast, in an Italian trial by Borghi and colleagues in 1996, in which the treated group kept urine volume above 2 L a day over five years, recurrence was 12% vs 27%.
Urgency, frequency and nocturia rose with the intervention, which may help explain why people find it hard to keep drinking. The commentators conclude that effective prevention needs a real rise in urine volume, together with diet (sodium, protein and oxalate) and, for some patients, alkali or other medicines.
Why it matters
Our take: water advice alone isn't a plan. If you want to know whether the advice is working, check a 24-hour urine volume.
Caveats
This is a commentary, and the comparison with a small trial from the 1990s is indirect. The trial itself was large and well designed, and its result stands for the strategy it tested.
Funding and ties: PUSH was funded by the NIDDK. The commentators declare no competing interests.
The source: Letavernier E, Drüeke TB. Kidney stone disease: to drink or not to drink—that is the question. Kidney Int. 2026;110:1078-1080. doi:10.1016/j.kint.2026.07.025 Read the original
Also discussed:
- Desai AC, et al. Prevention of urinary stones with hydration: a randomised clinical trial of an adherence intervention (PUSH). Lancet. 2026;407:1171-1181. doi:10.1016/S0140-6736(25)02637-6 Link
🎧 Listen: Weekly · Oct 26, from 12:35.
Physician-led, AI-assisted. Dr. Wael Hussein chooses every item NephSpace covers and reviews and edits every story before it is published. The first draft was written in our own words with AI (Claude, by Anthropic) from the full text of the commentary and the trial's published abstract and checked against our reading notes; Dr. Hussein then reviewed and edited it. For education and information only, not medical advice. Please talk to your own physician or care team about your health. Clinicians: read the original before changing practice. See our disclaimer and disclosures. Spotted an error? Tell us.
