Monthly Variations in Urolithiasis Presentations and Their Association with Meteorologic Factors in New York City

Introduction: Nephrolithiasis in the United States has been on the rise during the past several decades. Temperature has been shown to directly correlate with increased stone disease. We examine the association between climactic factors and monthly urolithiasis presentation rates for 6 years at a single institution in New York City. Methods: Emergency department (ED) data on patient visitations were collected along with patient demographics. Meteorological data were collected using the website Weather Underground (www.wunderground.com). Average monthly temperature, dew point, precipitation, and sea level pressure were obtained and relative humidity was calculated using the dew point. Monthly urolithiasis visitations and the correlation of atmospheric factors were analyzed using an autoregressive integrated moving average (ARIMA) model. Results: The total number of renal colic visits to the hospital\u27s ED from January 2007 through December 2012 tallied 3647 visits. The lowest average monthly rate per 1000 ED visits occurred in the month of February (28.8) and the highest in the month of August (43.8). There was a strong correlation between monthly presentation rate and temperature (