A Population Based Study of the Changing Demographics of Patients Undergoing Definitive Treatment for Kidney Stone Disease

Purpose: We examined temporal changes in the demographics of patients undergoing definitive treatment for kidney stones during a 20-year period in Ontario, Canada. Materials and Methods: Using the Ontario Health Insurance Plan physician claims database and the Canadian Institute for Health Information Discharge Abstract Database we performed a population based cross-sectional time series analysis by identifying all kidney stone treatments done between July 1, 1991 and December 31, 2010. The demographics assessed were patient gender, age and socioeconomic status. The rate and/or proportion of kidney stone treatments per strata of these demographics were calculated for each 1-year block of the study period. We used time series analysis with exponential smoothing and autoregressive integrated moving average models to assess for trends with time. Results: We identified 116,115 patients who underwent treatment for kidney stones during the study period. The rate of stone procedures performed per year increased steadily from 85/100,000 to 126/100,000 population. With time the rate of females who were treated increased significantly from 40/100,000 to 53/100,000 (p < 0.0001). In contrast, the rate of males who were treated remained stable, increasing from 82/100,000 to 83/100,000 (p = 0.11). In regard to age the rate of patients older than 64 years increased significantly with time from 67/100,000 to 89/100,000 (p < 0.0001). In regard to socioeconomic status approximately 20% of the patients were in each of the 5 income quintiles during the entire study period. Conclusions: Our population based study shows an increased rate of females and of patients older than 64 years undergoing definitive treatment for kidney stones with time.