Outcome of metabolic evaluation and medical treatment for calcium nephrolithiasis in a private urological practice.

Abstract

We determine if medications that have been proven effective for kidney stone prevention in prospective controlled trials can reduce kidney stone recurrence in a private practice of urology better than life-style advice, including hydration. Between July 1, 1995 and December 31, 1996, 203 patients with stones received care from 1 private practice. Physicians chose to evaluate these patients metabolically based on clinical judgement. Thiazide, potassium citrate and allopurinol are recognized in this study as active treatments, and drug treatment intervals were calculated. Relapse and recurrent stones were counted as those stones manifesting after the initial index event. A stone was called a relapse stone if its date was included in the active treatment interval. The association between use of active therapy and ordering of metabolic evaluation was highly significant. Using survival tables, we separately considered all patients and only those who had formed more than 1 stone. For both populations active treatment reduced stone recurrence significantly more than diet advice and hydration. Medications validated in trials and guided by metabolic evaluation lower stone recurrence when used in a private practice setting as they do in trials.