Philippe Gamache

Health inequalities in urban and rural Canada: Comparing inequalities in survival according to an individual and area-based deprivation index

Social health inequalities are smaller in rural than urban areas because, some argue, peoples social conditions are estimated at a small-area level, hiding variability at the individual or household level. This paper compares inequalities in survival according to an individual and area-based version of a deprivation index among a large sample of Canadians living in various urban and rural settings. Results show that survival inequalities in small towns and rural areas are lower than elsewhere when an area-based index is used, except in the remote hinterland, but of equal magnitude when the individual version of this index is considered.

Recent changes in the geography of social disparities in premature mortality in Québec

Most recent research reveals that social inequalities in premature mortality are widening. Such findings mainly apply to countries as a whole. In this study, we model recent changes in the association between premature mortality and a deprivation index (a small area-based index) in four geographic settings in Québec, namely the Montréal metropolitan area, other Québec metropolitan areas, mid-size cities, and small towns and rural areas. Deaths from all-cause and specific causes of mortality among people under age 75 are considered for the periods 1989-1993 and 1999-2003. Mortality rates are modeled using negative binomial regressions. Models are fitted for the overall population and for men and women, separately, in every geographic setting. Three measures of inequalities are used: mortality rates for different population groups, rate ratios and rate differences. Results show that social inequalities in premature mortality increase everywhere in Québec except in the Montréal metropolitan area. Presently, the highest mortality rates among deprived groups are found in mid-size cities, small towns and rural areas; the highest rate ratios in the Montréal metropolitan area and other metropolitan areas of Québec; and the highest rate differences in the Montréal metropolitan area, other metropolitan areas of Québec and mid-size cities. These results are discussed with reference to possible explanatory factors, namely relative deprivation, smoking, immigration and internal migration. Indications on future research and policy implications are provided.

Individual and area socioeconomic inequalities in cause-specific unintentional injury mortality: 11-Year follow-up study of 2.7 million Canadians

This study investigated the association between individual and area socioeconomic status (SES) and leading causes of unintentional injury mortality in Canadian adults. Using the 1991-2001 Canadian Census Mortality Follow-up Study cohort (N=2,735,152), Cox proportional hazard regression was used to calculate hazard ratios and 95% confidence intervals for all-cause unintentional injury, motor vehicle collision (MVC), fall, poisoning, suffocation, fire/burn, and drowning deaths. Results indicated that associations with SES differed by cause of injury, and were generally more pronounced for males. Low education was associated with an elevated risk of mortality from all-cause unintentional injury and MVC (males only) and poisoning and drowning (both sexes). Low income was strongly associated with most causes of injury mortality, particularly fire/burn and poisoning. Having no occupation or low occupational status was associated with higher risks of all-cause injury, fall, poisoning and suffocation (both sexes) and MVC deaths among men. Associations with area deprivation were weak, and only areas with high deprivation had elevated risk of all-cause injury, MVC (males only), poisoning and drowning (both sexes). This study reveals the importance of examining SES differentials by cause of death from a multilevel perspective. Future research is needed to clarify the mechanisms underlying these differences to implement equity-oriented approaches for reducing differential exposures, vulnerability or consequences of injury mortality.

Weighing the contributions of material and social area deprivation to preterm birth

Evidence suggests that individual socioeconomic status is a better predictor of preterm birth (PTB) than other individual social characteristics, but it is not clear if socioeconomic (material) area context is likewise more strongly related to PTB than social area characteristics. We compared material and social area deprivation to determine which was more strongly associated with PTB. Live singleton births from Québec, Canada were obtained for 1999-2006 (N = 581,898). PTB was defined as <37 completed gestational weeks. Two composite indices representing area-level material and social deprivation were used in Cox proportional hazards regression models to compute hazard ratios (HR) and 95% confidence intervals (CI) for PTB, accounting for individual-level characteristics including maternal education. Results indicated that PTB rates were higher for areas with high material (7.1%) and social (6.8%) deprivation than those with low material (5.5%) and social (5.9%) deprivation. Adjusted hazards of PTB were slightly greater for material deprivation than social deprivation. These findings indicate that material area deprivation is marginally more strongly associated with PTB than social deprivation, but it is not clear that interventions to prevent PTB should focus on material deprivation any more than on social area deprivation.

Influence of social and material individual and area deprivation on suicide mortality among 2.7 million Canadians: A prospective study

BackgroundFew studies have investigated how area-level deprivation influences the relationship between individual disadvantage and suicide mortality. The aim of this study was to examine individual measures of material and social disadvantage in relation to suicide mortality in Canada and to determine whether these relationships were modified by area deprivation.MethodsUsing the 1991-2001 Canadian Census Mortality Follow-up Study cohort (N = 2,685,400), measures of individual social (civil status, family structure, living alone) and material (education, income, employment) disadvantage were entered into Cox proportional hazard models to calculate hazard ratios (HR) and 95% confidence intervals (CI) for male and female suicide mortality. Two indices of area deprivation were computed - one capturing social, and the other material, dimensions - and models were run separately for high versus low deprivation.ResultsAfter accounting for individual and area characteristics, individual social and material disadvantage were associated with higher suicide mortality, especially for individuals not employed, not married, with low education and low income. Associations between social and material area deprivation and suicide mortality largely disappeared upon adjustment for individual-level disadvantage. In stratified analyses, suicide risk was greater for low income females in socially deprived areas and males living alone in materially deprived areas, and there was no evidence of other modifying effects of area deprivation.ConclusionsIndividual disadvantage was associated with suicide mortality, particularly for males. With some exceptions, there was little evidence that area deprivation modified the influence of individual disadvantage on suicide risk. Prevention strategies should primarily focus on individuals who are unemployed or out of the labour force, and have low education or income. Individuals with low income or who are living alone in deprived areas should also be targeted.

Relative and Absolute Disparities in Preterm Birth Related to Neighborhood Education

PURPOSE To evaluate relative and absolute relationships between preterm birth (PTB) and neighborhood education over time. METHODS Live births in Québec, Canada, were obtained for 1990-1995, 1996-2000, and 2001-2006. Mean maternal education and proportion of females with no high school diploma were expressed as continuous cumulative rank scores for 10,923 neighborhoods. We estimated the relative hazard of PTB (<37 gestational weeks) for neighborhood education in each period by using Cox proportional hazards regression, accounting for individual education, age, marital status, birthplace, language, parity, infant sex, rurality, neighborhood income, and area clustering. Adjusted absolute differences in the prevalence of PTB between the most and least educated neighborhoods were calculated. RESULTS PTB prevalence (6.1% overall) was greater in less-educated neighborhoods. Although PTB proportions increased over time in all neighborhoods, the increase was proportionately greater for less-educated areas. Hazards of PTB for neighborhood education were proportional over gestation. Depending on the indicator of neighborhood education and period, adjusted hazards of PTB were 10%-37% greater for the least relative to most educated neighborhoods, and prevalence percentage differences ranged from 0.6% to 1.9%. Associations persisted over time. CONCLUSIONS Relative and absolute neighborhood educational inequalities in PTB, independent of individual education, were present and persistent over time.

Leading causes of unintentional injury and suicide mortality in Canadian adults across the urban-rural continuum

Objective. We examined the leading causes of unintentional injury and suicide mortality in adults across the urban-rural continuum. Methods. Injury mortality data were drawn from a representative cohort of 2,735,152 Canadians aged ≥25 years at baseline, who were followed for mortality from 1991 to 2001. We estimated hazard ratios and 95% confidence intervals for urban-rural continuum and cause-specific unintentional injury (i.e., motor vehicle, falls, poisoning, drowning, suffocation, and fire/burn) and suicide (i.e., hanging, poisoning, firearm, and jumping) mortality, adjusting for socioeconomic and demographic characteristics. Results. Rates of unintentional injury mortality were elevated in less urbanized areas for both males and females We found an urban-rural gradient for motor vehicle, drowning, and fire/burn deaths, but not for fall, poisoning, or suffocation deaths. Urban-rural differences in suicide risk were observed for males but not females. Declining urbanization was associated with higher risks of firearm suicides and lower risks of jumping suicides, but there was no apparent trend in hanging and poisoning suicides. Conclusion. Urban-rural gradients in adults were more pronounced for unintentional motor vehicle, drowning, and fire/burn deaths, as well as for firearm and jumping suicide deaths than for other causes of injury mortality These results suggest that the degree of urbanization may be an important consideration in guiding prevention efforts for many causes of injury fatality.

Suicide in Canada: impact of injuries with undetermined intent on regional rankings.

The impact of underreporting or misclassifying suicides as injuries with undetermined intent is rarely evaluated. We assessed whether undetermined injury deaths influenced provincial rankings of suicide in Canada, using 2 735 152 Canadians followed for mortality from 1991 to 2001. We found that suicide rates increased by up to 26.5% for men and 37.7% for women after including injuries with undetermined intent, shifting provincial rankings of suicide. Attention to the stigma of suicide and to coding suicides as injuries with undetermined intent is merited for surveillance and prevention.