Clinical risk index in urolithiasis.

Various risk indices have been propounded by various authors to assess the severity of stone formation in the human urinary tract. However, most of these indices are laboratory oriented and not feasible to be performed in a hospital setting. Most of these also do not take into consideration all the possible influences on stone formation. In this paper, the correlation of various clinically relevant risk indices has been assessed to understand the relevance of the prediction in the possibility of future stone formation. 500 stone patients were studied to find out the various possible risk factors. The total score of the index was fixed as 100. Forty three variables were used to calculate the index, and each variable was given a score ranging from one to eight. They included the following: age 20-40 (1), sex (2), family history (3), Gulf returned (1), external occupation (1), primary (1), recurrent (5), symptoms (2), RBC (1), PC (1), COD (1), COM (2), UA (2), crystal aggregation (2), urinary infection (1), pH below 6 (1), bilateralism (2), kidney/U/B/U (1), passer (2), multiple organs (2), multiple number (2), incomplete removal (5), serum calcium (3), serum phosphorus (1), serum magnesium (1), serum creatinine (1), serum uric acid (4), urine volume (1), urine specific gravity (1), urine calcium (1), urine phosphorus (1), urine uric acid (5), urine magnesium (2), urine oxalate (8), urine citrate (8), calcium magnesium ratio (2), creatinine clearance (1), tubular reabsorption of phosphate (4), urine calcium oxalate ratio (2), urine oxalate citrate ratio (5), urine oxalate uric acid ratio (2), urine calcium uric acid ratio (2), stone COM/COD (2) and stone UA/cystine (2). After calculating the index, it was correlated with the clinical severity index. The severity status of each patient was considered as +/++/+++/++++ (nil/low/moderate/severe) depending on the status of the disease in long term assessment. In 127 patients, the risk index was calculated after a period of over 1 year to see the change in index score. On calculating the risk index and correlating with the severity grade of the stone disease, the correlation coefficient r value was +0.67 which was significant at P < 0.001 level. The risk index could be altered by dietary habit changes, drugs, life style changes, and appropriate drug schedules. The second assessment after 1 year of the 127 patients showed that the mean risk index could be reduced from 43.08 to 36.56. This difference was statistically significant (P < 0.01). It is concluded that by using the present clinical risk index assessment, it is possible to arrive at a prediction regarding future stone formation in any individual. It is also possible to reduce the risk of stone formation by dietetic and life style changes and appropriate chemotherapeutic drugs.