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Canadian Journal of Public Health

, Volume 97, Issue 2, pp 114–117 | Cite as

Prognostic Relevance of Census-derived Individual Respondent Incomes Versus Household Incomes

  • Danielle A. Southern
  • Peter D. Faris
  • Merril L. Knudtson
  • William A. GhaliEmail author
Research

Abstract

Background

Census-based measures of income derived from median income of a geographic area are often used in health research. Many national census surveys gather information on both the respondent’s individual income and the income for the entire household, giving researchers a choice of census income measures. We compared the extent to which individual respondent income and household income (both obtained from census data) are associated with outcomes in a cohort of patients with cardiac disease.

Methods

We used data from the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH), where postal codes were linked to the Postal Code Conversion File (PCCF) to determine each patient’s census Dissemination Areas (DA). DAderived median household income and median individual income were obtained from the 2001 Canadian Census and survival outcomes were then directly determined for income groupings defined by quintile. Two-year survival adjusted for age and sex was described with a proportional hazards analysis.

Results

There were 9,397 patients undergoing cardiac catheterization between January 1, 2001 and March 31, 2002, with complete DA-level median income measures. Household income quintiles yielded a wider spread of survival across quintiles (range of 2-year estimated survival, 91.8% to 95.9% for household income versus 92.8% to 95.6% for respondent income), as well as a more progressive decline in survival as income decreased. This progressive decline was not seen for the respondent income measure.

Conclusions

The greater spread and progressive decline of survival for household income relative to respondent income leads us to conclude that household income is the better socio-economic determinant of health in our data and for the outcome measure we studied.

MeSH terms

Censuses socioeconomic status income survival analysis registries 

Résumé

Contexte

Les mesures basées sur le recensement du revenu dérivé du revenu médian d’un secteur géographique sont souvent employées dans la recherche de la santé. Beaucoup d’enquêtes nationales de recensement recueillent l’information sur le revenu individuel du répondant ainsi que le revenu pour le ménage entier, donnant aux chercheurs un choix de mesures de revenu. Nous avons comparé le point auquel le revenu individuel du répondant et le revenu du ménage (tous les deux obtenus à partir de données de recensement) sont associés aux résultats dans une cohorte de patients présentant pour une cathérisation cardiaque.

Méthodes

Nous avons employé des données du projet Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH), où des codes postaux ont été liés au fichier de conversion des codes postaux plus (FCCP+) pour déterminer les aires de diffusion (AD) du recensement de chaque patient. Le revenu du ménage médian dérivé des AD et le revenu individuel médian ont été obtenus à partir du recensement du Canada de 2001, et des résultats de survie ont été directement déterminés pour des groupements de revenu définis par quintile. La survie de deux ans ajustée à l’âge et au sexe a été décrite avec une analyse de risques proportionnels.

Résultats

Il y avait 9 397 patients subissant la cathérisation cardiaque entre le 1 janvier, 2001 et le 31 mars, 2002, avec des mesures médianes de revenu de niveau des AD complets. Les quintiles de revenu du ménage ont rapporté une diffusion plus large de survie à travers des quintiles (tranche de survie de 2 ans estimé varie de 91,8 % à 95,9 % pour le ménage, et de 92,8 % à 95,6 % pour le répondant), aussi bien qu’un déclin plus progressif dans la survie pendant que le revenu diminue. Ce même déclin n’a pas été vu pour la mesure de revenu du répondant.

Interprétation

La diffusion plus grande et le déclin progressif de la survie pour le revenu du ménage par rapport à celui du répondant nous mènent à conclure que le revenu du ménage représente mieux le statut socio-économique comme déterminant de la santé dans nos données, et pour le résultat que nous avons évalué.

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Copyright information

© The Canadian Public Health Association 2006

Authors and Affiliations

  • Danielle A. Southern
    • 1
    • 2
  • Peter D. Faris
    • 3
  • Merril L. Knudtson
    • 2
  • William A. Ghali
    • 1
    • 2
    Email author
  1. 1.Department of Community Health SciencesUniversity of CalgaryCalgaryCanada
  2. 2.Department of Cardiac SciencesUniversity of CalgaryCalgaryCanada
  3. 3.Centre for Health and Policy StudiesUniversity of CalgaryCalgaryCanada

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