Community-level income inequality and mortality in Québec, Canada.
OBJECTIVE
Evidence of the association between income inequality and mortality for small rather than large areas is conflicting. This study evaluated community-level income inequality in relation to age- and cause-specific mortality.


METHODS
Ecological analysis.


METHODS
Mortality data were extracted from the Québec, Canada registry for 1999-2003. For Québec communities (n=143), directly standardized mortality rates were calculated for all-cause (overall, working-age and post-working-age), suicide, alcohol, tobacco and cardiovascular mortality. Using 2001 Canada Census data, the tertiles of income inequality measured as the decile ratio, coefficient of variation and median share were calculated. The relative risk (RR) of death was determined using Poisson regression, accounting for median community income, family structure and rural-urban area.


RESULTS
Income inequality was most strongly associated with alcohol-related mortality (RR(CoefficientVariation) 0.85, 95% confidence interval 0.77-0.94), followed by statistically significant but weaker inverse associations with tobacco-related and age-specific all-cause mortality.


CONCLUSIONS
Income inequality in Québec communities is inversely associated with mortality outcomes, particularly alcohol-related mortality. These associations contrast with positive or null associations observed in studies of larger US and Canadian metropolitan areas, respectively. Community-level studies accounting for individual-level covariates are necessary to clarify the relationship between income inequality and mortality.
Auger
N
N
Unité Etudes et analyses de l'état de santé de la population, Institut national de santé publique du Québec, Montréal, Québec, Canada. nathalie.auger@inspq.qc.ca
Zang
G
G
Daniel
M
M
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000428:Alcohol Drinking / Q000401:mortality; D002648:Child; D002675:Child, Preschool; D005260:Female; D054624:Health Status Disparities; D006801:Humans; D007182:Income; D007223:Infant; D008297:Male; D008875:Middle Aged; D009026:Mortality / Q000639:trends*; D011792:Quebec / Q000453:epidemiology; D012111:Residence Characteristics; D012923:Social Class