Stone formers often present with active disease and high burden of recurrence, entailing an increased risk of worsening renal function. In these patients, a pharmacological approach to kidney stone disease might be beneficial. However, data on the relative efficacy of available pharmacological approaches from direct comparisons are lacking.
Network meta-analysis (NMA) is a statistical technique that allows to obtain indirect estimates of different therapeutic approaches by common comparators. We performed a random-effects NMA of randomized controlled trials (RCTs) aimed at recurrence reduction in patients with idiopathic calcium stones. To be included in the analysis, at least one trial arm had to offer a pharmacological treatment. Estimates were calculated as risk ratios (RRs) and 95% confidence intervals (CIs).
11 RCTs were included in the analysis. Of these, 5 evaluated thiazides, 4 citrate and 2 allopurinol, all of them against diet/placebo. Compared with citrate, both thiazides (RR 2.11, CI 1.13, 3.92) and allopurinol (RR 2.41, CI 1.25, 4.63) were less effective in reducing recurrences. When compared with each other, the effect of thiazides and allopurinol was similar (Figure 1). Heterogeneity was not statistically significant.
Indirect comparisons obtained by NMA suggest that citrate might be more effective than thiazide and allopurinol in reducing recurrences in patients with idiopathic calcium stones.
