Prevention of recurrent calcium nephrolithiasis

Calcium-containing renal calculi are the most common stone type in reported series and recur in 26-53% of patients over a 10 year period. Because of this tendency, interventions aimed at reducing or preventing recurrence are an important strategy for reducing the morbidity associated with stone disease. This guideline uses an evidence-based review of the published literature with the purpose of examining current interventions aimed at reducing the recurrence of calcium stones. The approach to this and the other related CARI guidelines is to score interventions on the quality of the evidence available. Formal guidelines are made when Level I or II evidence is available (i.e. randomized controlled trial (RCT) or meta-analysis). It is appreciated that not all interventions used for stone prevention may be adequately represented by this approach. Part of the funcion of this review is therefore to highlight where the available evidence for treatment of this condition can be improved. Similarly, detailed discussion of the different metabolic abnormalities seen in patients with recurrent calcium stones is beyond the scope of this review. Where applicable, however, the role of different interventions in the presence of different metabolic abnormalities is discussed. Evidence based recommendations for the interventions considered in this review were only made where data available for their effect on stone recurrence. Recommendations were not made when the effect of an intervention on surrogate markers of stone risk (e.g. urinary parameters) was reported.