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

Abstract

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.