title: The use of Bayesian inference to inform the surveillance of temperature-related occupational morbidity in Ontario, Canada, 2004-2010.
abstract: OBJECTIVE
  To assess the associations of occupational heat and cold-related illnesses presenting in emergency departments in south western Ontario, Canada, with daily meteorological conditions using Bayesian inference.
  
  
  METHODS
  Meteorological and air pollution data for the south western economic region of Ontario were gathered from Environment Canada and the Ministry of Environment. Daily heat and cold-related emergency department visits clinically attributed to work from 2004 to 2010 were tabulated. A novel application of Bayesian inference on a flexible Poisson time series model was undertaken to examine linear and non-linear associations between average, regional meteorological conditions and daily morbidity rates, to adjust for relevant confounders and temporal trends, and to consider potential interactions.
  
  
  RESULTS
  Bilinear associations were observed between regional temperatures and morbidities resulting from extreme temperature exposures. The median increase in the daily rate of emergency department visits for heat illness was 75% for each degree above 22°C (posterior 95% credible interval (CI) relative rate=1.56-1.99) in the daily maximum temperature. Below 0°C, rates of occupational cold illness increased by a median of 15% for each degree decrease in the minimum temperature (posterior 95% CI 0.80-0.91); wind speed also had a significant effect.
  
  
  CONCLUSIONS
  The observed associations can inform occupational surveillance and injury prevention programming, as well as public health efforts targeting vulnerable populations. Methodologically, the use of Bayesian inference in time series analyses of meteorological exposures is feasible and conducive to providing accurate advice for policy and practice.
authors.affiliation: Institute for Work & Health, 481 University Avenue, Suite 800, Toronto, ON, Canada M5G 2E9; Partnership for Work, Health & Safety, School of Population and Public Health, University of British Columbia, 2206 East Mall, Vancouver, BC, Canada V6T 1Z3. Electronic address: mfortune@iwh.on.ca.
authors.forename: Melanie
authors.initials: M
authors.lastname: Fortune
authors.affiliation: Institute for Work & Health, 481 University Avenue, Suite 800, Toronto, ON, Canada M5G 2E9; Dalla Lana School of Public Health, University of Toronto, 155 College Street, 6th Floor, Toronto, ON, Canada M5T 3M7. Electronic address: cmustard@iwh.on.ca.
authors.forename: Cameron
authors.initials: C
authors.lastname: Mustard
authors.affiliation: Cancer Care Ontario, 525 University Avenue, Toronto, ON, Canada M5G 2L3; Dalla Lana School of Public Health, University of Toronto, 155 College Street, 6th Floor, Toronto, ON, Canada M5T 3M7. Electronic address: patrick.brown@utoronto.ca.
authors.forename: Patrick
authors.initials: P
authors.lastname: Brown
mesh_terms: D001499:Bayes Theorem; D003080:Cold Temperature / Q000009:adverse effects*; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D016273:Occupational Exposure / Q000009:adverse effects / Q000706:statistics & numerical data*; D009864:Ontario; D011159:Population Surveillance
keywords: Bayesian inference; Epidemiology; Occupational exposures; Surveillance; Temperature