Real-World Effectiveness of Preventive Pharmacological Therapy in Patients With Urolithiasis: A Retrospective Cohort Study
In a large real-world Medicare cohort, adherence to guideline-concordant preventive pharmacological therapy was associated with significantly fewer symptomatic stone events in patients with hypercalciuria (thiazides) and low urine pH (alkali), but not in those with hypocitraturia or hyperuricosuria.
Background
Evidence for preventive pharmacological therapy (PPT) in urolithiasis has largely rested on trials using composite outcomes that include imaging findings of uncertain clinical significance. Despite guideline support, agents such as thiazides and alkali therapy remain infrequently prescribed, in part due to limited data on their real-world effectiveness against clinically meaningful stone events.
Study design
This retrospective cohort study analyzed 13,942 Medicare enrollees with urolithiasis who completed 24-hour urine collections revealing hypercalciuria, hypocitraturia, low urine pH, or hyperuricosuria. Patients were categorized as adherent to guideline-concordant PPT, nonadherent, or untreated, and the primary outcome was a symptomatic stone event (emergency department visit, hospitalization, or stone-directed surgery), assessed using Cox proportional hazards regression. Overall, 31% of patients were prescribed PPT.
Key findings
Compared with no treatment, concordant and adherent PPT was associated with a significantly lower hazard of symptomatic stone events in patients with hypercalciuria (HR 0.736; 95% CI 0.593-0.915) and low urine pH (HR 0.804; 95% CI 0.650-0.996), but not in those with hypocitraturia or hyperuricosuria. The benefit was largely driven by fewer emergency department visits; for hypercalciuria, the 2-year predicted probability of a visit was 3.8% with adherent PPT versus 6.9% untreated, and for low urine pH, 4.3% versus 7.3%.
Clinical implications
These real-world data support prescribing and reinforcing adherence to thiazide diuretics for hypercalciuria and alkali therapy for low urine pH as effective secondary prevention of symptomatic kidney stones. The findings should encourage greater uptake of these underused therapies, while the lack of benefit for hypocitraturia and hyperuricosuria in this analysis highlights remaining uncertainty. The authors note potential confounding if treated patients had more severe disease than untreated patients.
Category
Research
Source
American Journal of Kidney Diseases
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