The assessment of 24 24-h urine volume by measurement of urine specific gravity with dipstick in adults with nephrolithiasis

BACKGROUND: Nephrolithiasis is a recurrent disease, and one of the most effective methods for prevention of stone recurrence is increasing the urine output (>2 L/day), but it is difficult to achieve it. The aim of this study was to evaluate the effect of behavioral intervention by measurement of urine specific gravity using dipstick on 24-h urine volume in first renal stone patients. MATERIALS AND METHODS: In this prospective randomize clinical study, 80 adult patients with history of first renal stone were included. Patients were divided into two groups with 40 patients in each group. We explained the importance of high fluid intake and high urine volume in the prevention of renal stones for all patients. Group A patients were trained to measure 24-h urine volume every 15 days, and group B patients were trained to keep urine specific gravity below 1.010 by using dipstick. We measured 24-h urine volume in each group before intervention, and at 3 months and 6 months after intervention and compared them. RESULTS: There were no significant differences between the two groups in 24-h urine volume before intervention (P = 0.41), but it was significant 3 months (P = 0.01) and 6 months (P = 0.01) after intervention. Patients’ compliance was 20% in group A and 90% in group B (P < 0.05). CONCLUSION: The use of behavioral modification with dipstick is an effective method for control and maintenance of optimal urine volume, and it has resulted in more patient compliance for drinking water and is more effective for prevention of renal stone.