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.