title: Influenza and pneumonia hospitalizations in Ontario: a time-series analysis.
abstract: A comprehensive examination of gender and age-specific influenza and pneumonia hospitalization seasonality is currently lacking. Using population-based data for Ontario, Canada between April 1988 and March 2002 (n = 339,803 hospitalizations), findings from this study revealed clear seasonality [Fisher's Kappa (FK) test = 68.64, P < 0.001; Bartlett's Kolmogorov-Smirnov (BKS) test = 0.68, P < 0.001] with consistent summer troughs and winter peaks for both sexes and all ages combined. The very young (both sexes 0-4 years) demonstrated the strongest seasonality (R2(autoreg) = 0.97) and females aged 10-19 years, the weakest (R2(autoreg) = 0.59). Gender differences were most pronounced in the oldest age groups (80+ years) where females had an average annualized peak rate of 250/100,000 compared to 400/100,000 for males. These findings can contribute to more population-specific prevention strategies and effective resource and service allocation based on seasonal and specific population demands.
authors.affiliation: Primary Care Research Unit, Sunnybrook and Women's College Health Sciences Centre, Toronto, ON, Canada. eric.crighton@sw.ca
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Crighton
authors.forename: Rahim
authors.initials: R
authors.lastname: Moineddin
authors.forename: Muhammad
authors.initials: M
authors.lastname: Mamdani
authors.forename: Ross E G
authors.initials: RE
authors.lastname: Upshur
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007251:Influenza, Human / Q000453:epidemiology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009864:Ontario / Q000453:epidemiology; D011014:Pneumonia / Q000453:epidemiology* / Q000628:therapy*; D012189:Retrospective Studies; D012621:Seasons; D012737:Sex Factors