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Canadian Journal of Public Health

, Volume 94, Issue 6, pp 453–457 | Cite as

The Seasonality of Total Hospitalizations in Ontario by Age and Gender

A Time Series Analysis
  • Eric J. CrightonEmail author
  • Rahim Moineddin
  • Ross E. G. Upshur
  • Muhammad Mamdani
Article

Abstract

Background

Consistent and predictable seasonal fluctuations in hospitalizations have been demonstrated for diverse communicable and non-communicable health conditions. The objective of this study was to examine the seasonal patterns of all hospitalizations by age and gender in order to determine whether the hospital system for a large geographical area was subject to consistent, predictable temporal variations.

Methods

A retrospective population-based study of approximately 14 million residents of Ontario was conducted to assess temporal patterns in all hospitalizations from April 1, 1988 to March 31, 2000. Time series analysis, using spectral analysis, was conducted to assess seasonal variations and trends over time and to account for autocorrelation.

Results

Conspicuous seasonality in hospitalizations was found in every age group for both sexes with the exception of males between the ages of 20 and 39. The average monthly variability ranged from lows of 15% for the age group 20–29 for both sexes, to highs of 34% in males between 5 and 9 years. For the total population, this represents a 12-year average variability of approximately 20% or 20,000 out of 97,000 hospitalizations. For both sexes, peak hospitalizations typically occurred in the spring and autumn for the youngest and oldest age groups, and in January for the middle age groups.

Conclusion

Seasonal factors play an important role in the utilization of hospital services in Ontario. The determinants of this seasonality, which include environmental and social/behavioural factors, are not well understood.

Résumé

Contexte

Des fluctuations saisonnières régulières et prévisibles du nombre d’hospitalisations ont été constatées pour divers troubles médicaux transmissibles et non transmissibles. Nous avons voulu examiner les schémas saisonniers selon l’âge et le sexe pour l’ensemble des hospitalisations afin de déterminer si l’appareil hospitalier d’une vaste zone géographique faisait l’objet de variations temporelles régulières et prévisibles.

Méthode

Une étude rétrospective fondée sur la population des résidents de l’Ontario (environ 14 millions de personnes) a permis d’évaluer les schémas temporels de l’ensemble des hospitalisations entre le 1er avril 1988 et le 31 mars 2000. Au moyen d’une analyse spectrale, nous avons analysé des séries chronologiques pour évaluer les variations saisonnières et les tendances au fil du temps et expliquer l’autocorrélation.

Résultats

Des cycles saisonniers apparents dans les hospitalisations ont été constatés dans tous les groupes d’âge et pour les deux sexes, sauf chez les hommes de 20 à 39 ans. La variabilité mensuelle moyenne présentait des creux de 15 % dans le groupe des 20 à 29 ans des deux sexes et des crêtes de 34 % chez les garçons de 5 à 9 ans. Pour l’ensemble de la population, ceci représente une variabilité moyenne d’environ 20 % sur 12 ans, soit 20 000 hospitalisations sur 97 000. Pour les deux sexes, on observe en général des crêtes d’hospitalisations au printemps et à l’automne dans les groupes les plus jeunes et les plus âgés, et en janvier dans les groupes d’âge moyen.

Conclusion

Les facteurs saisonniers jouent un rôle important dans l’utilisation des services hospitaliers en Ontario. Les déterminants de ces cycles saisonniers, dont des facteurs environnementaux et socio-comportementaux, sont encore mal compris.

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Copyright information

© The Canadian Public Health Association 2003

Authors and Affiliations

  • Eric J. Crighton
    • 1
    Email author
  • Rahim Moineddin
    • 2
  • Ross E. G. Upshur
    • 3
    • 5
  • Muhammad Mamdani
    • 4
    • 6
  1. 1.Primary Care Research UnitSunnybrook and Women’s College Health Sciences CentreTorontoCanada
  2. 2.Department of Family and Community MedicineUniversity of TorontoCanada
  3. 3.Primary Care Research UnitSunnybrook and Women’s College Health Sciences CentreCanada
  4. 4.Institute of Clinical Evaluative Sciences (ICES)Canada
  5. 5.Department of Family and Community Medicine and Public Health SciencesUniversity of TorontoCanada
  6. 6.Faculty of PharmacyUniversity of TorontoCanada

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