title: A multi-level approach for investigating socio-economic and agricultural risk factors associated with rates of reported cases of Escherichia coli O157 in humans in Alberta, Canada.
abstract: Using negative binomial and multi-level Poisson models, the authors determined the statistical significance of agricultural and socio-economic risk factors for rates of reported disease associated with Escherichia coli O157 in census subdivisions (CSDs) in Alberta, Canada, 2000-2002. Variables relating to population stability, aboriginal composition of the CSDs, and the economic relationship between CSDs and urban centres were significant risk factors. The percentage of individuals living in low-income households was not a statistically significant risk factor for rates of disease. The statistical significance of cattle density, recorded at a higher geographical level, depended on the method used to correct for overdispersion, the number of levels included in the multi-level models, and the choice of using all reported cases or only sporadic cases. Our results highlight the importance of local socio-economic risk factors in determining rates of disease associated with E. coli O157, but their relationship with individual risk factors requires further evaluation.
authors.affiliation: Department of Population Medicine, University of Guelph, Guelph, ON, Canada. dpearl@uoguelph.ca
authors.forename: D L
authors.initials: DL
authors.lastname: Pearl
authors.forename: M
authors.initials: M
authors.lastname: Louie
authors.forename: L
authors.initials: L
authors.lastname: Chui
authors.forename: K
authors.initials: K
authors.lastname: Doré
authors.forename: K M
authors.initials: KM
authors.lastname: Grimsrud
authors.forename: S W
authors.initials: SW
authors.lastname: Martin
authors.forename: P
authors.initials: P
authors.lastname: Michel
authors.forename: L W
authors.initials: LW
authors.lastname: Svenson
authors.forename: S A
authors.initials: SA
authors.lastname: McEwen
mesh_terms: D000416:Alberta / Q000453:epidemiology; D000818:Animals; D002417:Cattle; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology*; D019453:Escherichia coli O157; D006801:Humans; D015994:Incidence; D008954:Models, Biological; D016273:Occupational Exposure; D012307:Risk Factors; D012959:Socioeconomic Factors; D015047:Zoonoses