Regression Analysis for the Climate Effects on Seasonal Variations in the Urinary Lithotripsy: A Regional Hospital Based Study

We study the climate effects on seasonal variations in the amount of urinary lithotripsy operations using 6-year data in a regional hospital in northwestern Taiwan. From 2003 to 2008, 7660 procedures for upper tract urinary calculi are performed. These data are divided into subgroups by gender and age range (18-44, 44-65, >65). Five climate factors (ambient temperature, atmosphere pressure, relative humidity, hours of sunshine, and rainfall) are considered. The purpose of this study is for used in the future research aiming to predict the stone recurrence based on climate conditions and related items for this hospital. Unlike an earlier nationwide study, our results show that not only the ambient temperature but also the atmosphere pressure and relative humidity have significant effects on the amount of urinary lithotripsy operations. The difference may be due to the multicollinearity problem. Furthermore, we exclude the age group of 65 and older from the regression analysis because of its lack of seasonal variations.