Epidemiology of Upper Urinary Tract Stone Disease in a Taiwanese Population: A Nationwide, Population Based Study

Purpose: We investigated the epidemiology of upper urinary tract stone disease in Taiwan using a nationwide, population based database. Materials and Methods: This study was based on the National Health Insurance Research Database of Taiwan, which contains data on all medical beneficiary claims from 22.72 million enrollees, accounting for almost 99% of the Taiwanese population. The Longitudinal Health Insurance Database 2005, a subset of the National Health Insurance Research Database, contains data on all medical benefit claims from 1997 through 2010 for a subset of 1 million beneficiaries randomly sampled from the 2005 enrollment file. For epidemiological analysis we selected subjects whose claims records included the diagnosis of upper urinary tract urolithiasis. Results: The age adjusted rate of medical care visits for upper urinary tract urolithiasis decreased by 6.5% from 1,367/100,000 subjects in 1998 to 1,278/ 100,000 in 2010. There was a significantly decreasing trend during the 13-year period in visits from female and all subjects (r(2) = 0.86, p = 0.001 and r(2) = 0.52, p = 0.005, respectively). In contrast, an increasing trend was noted for male subjects (r(2) = 0.45, p = 0.012). The age adjusted prevalence in 2010 was 9.01%, 5.79% and 7.38% in male, female and all subjects, respectively. The overall recurrence rate at 1 and 5 years was 6.12% and 34.71%, respectively. Male subjects had a higher recurrence rate than female subjects. Conclusions: Our study provides important information on the epidemiology of upper urinary tract stone disease in Taiwan, helping to quantify the burden of urolithiasis and establish strategies to decrease the risk of urolithiasis.