Abstract
Objective: An imbalance in the distribution of economic resources, i.e., income inequality, is a characteristic of a community that may influence the aggregate health of the population. In North America, income inequality seems to be strongly related to mortality rates among American communities such as states and metropolitan areas but largely irrelevant for health at similar levels of geopolitical aggregation in Canada. This article summarizes relevant international and North American evidence and then explores relationships between income inequality and mortality rates among coastal communities in the province of British Columbia, Canada.
Methods: Cross-sectional analysis was conducted among twenty-four coastal communities in British Columbia, utilizing four measures based on the 1996 Census to measure income inequality and crude, age-standardized and age- and gender-specific mortality rates averaged over the five-year period 1994–98 to measure health.
Results: The three valid measures of income inequality were positively and significantly related to the crude mortality rate but were not significantly related to the agestandardized mortality rate. Two of the inequality measures were related to mortality rates for males aged 0–44 and for males aged 45–64 before but not after controlling for mean household income.
Discussion: Health researchers have yet to report a meaningful relationship between income inequality and population health within Canada. At the risk of committing the ecological fallacy, these findings provisionally support a psycho-social interpretation of the individual-level relationship between income and health wherein members of these communities compare themselves to an encompassing community, e.g., all Canadians.
Résumé
Objectif: La répartition inégale des ressources économiques (c.-à-d. l’inégalité des revenus) dans une collectivité est une caractéristique susceptible d’influencer la santé générale de la population. L’inégalité des revenus semble fortement associée aux taux de mortalité dans les collectivités comme les États et les zones métropolitaines aux États-Unis, mais au Canada, elle ne semble pas jouer sur l’état de santé dans les ensembles géopolitiques semblables. Nous faisons ici la synthèse des preuves pertinentes, en Amérique du Nord et dans le reste du monde, et nous étudions les liens entre l’inégalité des revenus et les taux de mortalité dans les collectivités côtières de la province canadienne de la Colombie-Britannique.
Méthode: Nous avons fait l’analyse transversale de 24 collectivités côtières de la Colombie-Britannique à l’aide de quatre indicateurs du recensement de 1996 afin de mesurer l’inégalité des revenus et les taux bruts de mortalité, sans strate d’âges, puis avec strates d’âges et de sexe. Nous avons fait la moyenne de ces taux sur cinq ans (1994–1998) pour mesurer l’état de santé.
Résultats: Les trois indicateurs valides d’inégalité des revenus étaient associés de façon positive et significative au taux brut de mortalité, mais non au taux de mortalité sans strate d’âges. Deux des indicateurs étaient associés aux taux de mortalité des hommes de 0 à 44 ans et de 45 à 64 ans avant rectification en fonction du revenu des ménages, mais ils ne l’étaient plus après.
Conclusion: Les chercheurs médicaux n’ont pas encore découvert de lien significatif entre l’inégalité des revenus et la santé de la population au Canada. Au risque d’être accusé de sophisme écologique, nous pensons que ces résultats appuient provisoirement une interprétation psychosociale du lien individuel entre le revenu et la santé, à savoir que les membres des collectivités en question se comparent à un ensemble global (p. ex., à tous les Canadiens).
Footnotes
Sources of support: Gerry Veenstra is supported by a New Investigator Award (2000–2005) from the Canadian Institutes of Health Research. The economic data for these communities were collected for the Resilient Communities Project, a project led by co-investigators Ralph Matthews, Brian Elliott and Gerry Veenstra at the University of British Columbia and funded by the Social Sciences and Humanities Research Council of Canada.
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