Comparison of Selective Versus Empiric Pharmacologic Preventative Therapy With Kidney Stone Recurrence

OBJECTIVE To assess the effectiveness of an empiric approach to metabolic stone prevention. METHODS Using medical claims from a cohort of working age adults with kidney stone diagnoses (2008-2017), we identified the subset who were prescribed thiazides, alkali therapy, or allopurinol-collectively known as preventive pharmacologic therapy (PPT). We distinguished between those who had 24-hour urine testing prior to initiating PPT (selective therapy) from those without it (empiric therapy). We conducted a survival analysis for time to first recurrence for stone- related events, including ED visits, hospitalizations, and surgery, up to 2 years after initiating PPT. RESULTS Of 10,125 patients identified, 2744 (27%) and 7381 (73%) received selective and empiric therapy, respectively. The overall frequency of any stone-related event was 11%, and this did not differ between the 2 groups on bivariate analysis (P =.29). After adjusting for sociodemographic factors, comorbidities, medication class, and adherence, there was no difference in the hazard of a stone-related event between the selective and empiric therapy groups (hazard ratio, 0.97; 95% confidence interval, 0.84-1.12). When considered individually, the frequency of ED visits, hospitalizations, and surgeries did not differ between groups. Greater adherence to PPT and older age were associated with a lower hazard of a stone-related event (both P <.05). CONCLUSION Compared to empiric therapy, PPT guided by 24-hour urine testing, on average, is not associated with a lower hazard of a stone-related event. These results suggest a need to identify kidney stone patients who benefit from 24-hour urine testing. (C) 2020 Elsevier Inc.

Automated summary

This study assessed the effectiveness of an empiric approach to metabolic stone prevention. The results showed that empiric therapy guided by 24-hour urine testing, on average, is not associated with a lower hazard of a stone-related event compared to selective therapy. However, greater adherence to preventive pharmacologic therapy and older age were associated with a lower hazard of a stone-related event.