Urinary stone risk factors in the siblings of patients with calcium renal stones.

Purpose: We determined which, if any, urinary stone risk factors accurately discriminate stone forming and nonstone forming siblings of patients with calcium renal stones.

Materials And Methods: A total of 252 siblings of stone formers provided 2, 24-hour urine samples, which were sent overnight and analyzed at a central laboratory. Standard stone risk factors were measured and the supersaturation of calcium oxalate, calcium phosphate and uric acid was calculated.