A large 15 - year database analysis on the influence of age, gender, race, obesity and income on hospitalization rates due to stone disease

PURPOSE: To assess the public hospitalization rate due to stone disease in a large developing nation for a 15-year period and its association with socio-demographic data. MATERIALS AND METHODS: A retrospective database analysis of hospitalization rates in the Brazilian public health system was performed, searching for records with a diagnosis code of renal/ureteral calculi at admission between 1998–2012. Patients managed in an outpatient basis or private care were excluded. Socio-demographic data was attained and a temporal trend analysis was performed. RESULTS: The number of stone-related hospitalizations increased from 15.7%, although the population-adjusted hospitalization rate remained constant in 0.04%. Male:female proportion among hospitalized patients was stable (49.3%:50.7% in 1998; 49.2%:50.8% in 2012), though there was a significant reduction in the prevalence of male hospitalizations (−3.8%;p=0.041). In 2012, 38% of hospitalized patients due to stone disease had 40–59 years-old. The ≥80 years-old strata showed the most significant decrease (−43.44%;p=0.022), followed by the 20–39 (−23.17%;p<0.001) and 0–19 years-old cohorts (−16.73%;p=0.012). Overall, the lowest relative hospitalization rates were found for yellow and indigenous individuals. The number of overweight/obese individuals increased significantly (+20.6%), accompanied by a +43.6% augment in the per capita income. A significant correlation was found only between income and obesity (R=0.64;p=0.017). CONCLUSIONS: The prevalence of stone disease requiring hospitalization in Brazil remains stable, with a balanced proportion between males and females. There is trend for decreased hospitalization rates of male, <40 and ≥80 years-old individuals. Obesity and income have a more pronounced correlation with each other than with stone disease.