title: Modeling and syndromic surveillance for estimating weather-induced heat-related illness.
abstract: This paper compares syndromic surveillance and predictive weather-based models for estimating emergency department (ED) visits for Heat-Related Illness (HRI). A retrospective time-series analysis of weather station observations and ICD-coded HRI ED visits to ten hospitals in south eastern Ontario, Canada, was performed from April 2003 to December 2008 using hospital data from the National Ambulatory Care Reporting System (NACRS) database, ED patient chief complaint data collected by a syndromic surveillance system, and weather data from Environment Canada. Poisson regression and Fast Orthogonal Search (FOS), a nonlinear time series modeling technique, were used to construct models for the expected number of HRI ED visits using weather predictor variables (temperature, humidity, and wind speed). Estimates of HRI visits from regression models using both weather variables and visit counts captured by syndromic surveillance as predictors were slightly more highly correlated with NACRS HRI ED visits than either regression models using only weather predictors or syndromic surveillance counts.
authors.affiliation: Public Health Informatics Group, Kingston, Frontenac, Lennox & Addington Public Health, 221 Portsmouth Avenue, Kingston, ON, Canada K7M 1V5. alexander.perry@queensu.ca
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Perry
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Korenberg
authors.forename: Geoffrey G
authors.initials: GG
authors.lastname: Hall
authors.forename: Kieran M
authors.initials: KM
authors.lastname: Moore
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D055874:Extreme Heat / Q000009:adverse effects*; D005260:Female; D005544:Forecasting; D018882:Heat Stress Disorders / Q000453:epidemiology*; D006801:Humans; D006813:Humidity / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D017711:Nonlinear Dynamics; D009864:Ontario / Q000453:epidemiology; D016012:Poisson Distribution; D011159:Population Surveillance / Q000379:methods*; D012044:Regression Analysis; D012189:Retrospective Studies; D013997:Time Factors; D014919:Wind; D055815:Young Adult