Underlying Causes of Ethnocultural Inequality in Pregnancy Outcomes: Role of Hospital Proximity.

We evaluated the contribution of place of birth to ethnocultural inequality in pregnancy outcomes. We analyzed a cohort of 1,487,723 births between 1998 and 2019 among minority Anglophones and majority Francophones in Quebec, Canada. We estimated the association (adjusted risk ratio, RR; 95% confidence interval, CI) of language with preterm birth and stillbirth, and incorporated interaction terms to determine the contribution of place of birth and distance traveled. Compared with Francophones, minority Anglophones had a greater risk of preterm birth (RR 1.03; 95% CI 1.01-1.06) and were less likely to deliver farther from home (RR 0.95; 95% CI 0.94-0.95). Anglophones who delivered close to home had a higher risk of preterm birth (RR 1.07; 95% CI 1.04-1.11), whereas Anglophones who delivered farther had a lower risk (RR 0.69; 95% CI 0.64-0.75). Patterns were similar for stillbirth. Ethnocultural inequality in adverse birth outcomes may be influenced by place of birth.

Ethnicity, Child Sex, and the Likelihood of Marriage in Pregnancy: A Novel Analysis of Gender Inequity.

Objective: We assessed the association between fetal sex and the likelihood of marriage during pregnancy. Methods: We analyzed a cohort of 1,334,911 women who were unmarried at conception and had a live birth between 1990 and 2018 in Quebec, Canada. The exposure was fetal sex, determined by ultrasound. The outcome was marriage during pregnancy. We estimated hazard ratios and 95% confidence intervals (CI) for the association of child sex with the likelihood of marriage during pregnancy according to region of origin. Results: Among women who were unmarried at conception, 13.1% of foreign-born women got married during pregnancy compared with 2.6% of Canadian-born women. Women from the Middle East and North Africa who were pregnant with boys were 1.13 times more likely to marry during pregnancy compared with women who were pregnant with girls (95% CI 1.02-1.26). There was no association among Canadian-born women. Conclusion: Women from some cultural minorities who are pregnant with boys may be more likely to marry during pregnancy in Western settings. Gender inequality may manifest as a preference for sons that influences the likelihood of marriage.

Stillbirth in Canada: anachronistic definition and registration processes impede public health surveillance and clinical care.

The archaic definition and registration processes for stillbirth currently prevalent in Canada impede both clinical care and public health. The situation is fraught because of definitional problems related to the inclusion of induced abortions at ≥20 weeks' gestation as stillbirths: widespread uptake of prenatal diagnosis and induced abortion for serious congenital anomalies has resulted in an artefactual temporal increase in stillbirth rates in Canada and placed the country in an unfavourable position in international (stillbirth) rankings. Other problems with the Canadian stillbirth definition and registration processes extend to the inclusion of fetal reductions (for multi-fetal pregnancy) as stillbirths, and the use of inconsistent viability criteria for reporting stillbirth. This paper reviews the history of stillbirth registration in Canada, provides a rationale for updating the definition of fetal death and recommends a new definition and improved processes for fetal death registration. The recommendations proposed are intended to serve as a starting point for reformulating issues related to stillbirth, with the hope that building a consensus regarding a definition and registration procedures will facilitate clinical care and public health.

RéSUMé: La définition et les méthodes d'enregistrement archaïques des mortinaissances qui prévalent actuellement au Canada entravent à la fois les soins cliniques et la santé publique. La situation est délicate à cause des problèmes de définition que pose l'inclusion des avortements provoqués à ≥ 20 semaines de gestation parmi les mortinaissances : le recours généralisé au diagnostic prénatal et les avortements provoqués en cas d'anomalies congénitales graves ont entraîné une augmentation temporelle artéfactuelle des taux de mortinatalité au Canada et placé le pays dans une position défavorable dans les classements internationaux (de la mortinatalité). Les autres problèmes dans la définition et les méthodes d'enregistrement canadiennes des mortinaissances sont l'inclusion de la réduction fœtale (pour les grossesses multifœtales) parmi les mortinaissances et l'emploi de critères de viabilité inconsistants pour déclarer les mortinaissances. Nous examinons ici l'histoire de l'enregistrement des mortinaissances au Canada, nous justifions une révision possible de la définition de la mort fœtale et nous recommandons une nouvelle définition et des méthodes d'enregistrement améliorées des morts fœtales. Les recommandations proposées se veulent un point de départ à une reformulation des questions liées à la mortinatalité, dans l'espoir que l'établissement d'un consensus sur une définition et sur les méthodes d'enregistrement facilitera les soins cliniques et la santé publique.

Tombstone size and life expectancy: a cross-sectional analysis of cemetery data before the turn of the century.

The extent to which socioeconomic status was associated with life expectancy in the 19th and early part of the twentieth century is poorly understood. We sought to determine the association between a deceased individual's tombstone size, a potential marker of socioeconomic status, and their age of death in the late modern period. We conducted a cross-sectional study of 276 deceased individuals buried between 1820 and 1992 in a large cemetery in Quebec, Canada. The main outcome measure was age of death. We used generalized linear models adjusted for sex, marital status, and year of death to determine whether tombstone height and volume were associated with a greater number of years lived. Tombstone height and volume were associated with an older age of death in adjusted regression models. Individuals with tall tombstones lived 9.6 years longer than those with short tombstones (95% confidence interval, CI 3.9 to 15.4). Individuals with large volume tombstones lived 6.2 years longer than those with small tombstones (95% CI 1.7 to 10.8). Our findings indicate that in the 1800s and early 1900s, tombstone size was strongly associated with age of death. A possible explanation for this occurrence is that wealthy individuals, capable of purchasing more sizeable tombstones, were more likely to live a longer and healthier life.

Infant mortality among Arabic-speakers in Quebec, Canada, 1989-2017.

BACKGROUND: We assessed trends in infant mortality for Arabic-speakers in Quebec, Canada between 1981 and 2017. METHODS: We computed infant mortality rates for Arabic versus French and English-speakers in Quebec over time. We used adjusted risk ratios (aRR) and 95% confidence intervals (CI) to investigate trends among Arabic-speakers according to socioeconomic status, age, and cause of death. RESULTS: Infant mortality rates were 3.0 for Arabic-speakers and 5.1 for French and English-speakers per 1,000 live births. Infant mortality increased for Arabic-speakers between 1989-1995 and 2010-2017 (aRR 2.07; 95% CI, 1.04-4.12), but decreased for French and English-speakers (aRR 0.77; 95% CI, 0.73-0.81). The increase in infant mortality was greater for socioeconomically advantaged Arabic-speakers (aRR 2.52; 95% CI, 1.20-5.28) and early neonatal mortality (aRR 1.64; 95% CI, 0.98-2.76). DISCUSSION: Arabic-speakers in Quebec have a lower risk of infant mortality than French and English-speakers, but increasing infant mortality among Arabic-speakers is narrowing the gap.

Emerging Lingo-Cultural Inequality in Infant Autopsy in Quebec, Canada.

We investigated trends in infant autopsy for Francophones and Anglophones in Quebec, Canada. Using death certificates, we extracted 8214 infant deaths between 1989 and 2013. We computed rates of non-autopsy by language, socioeconomic disadvantage, age at death, and period. Using Kitagawa's method, we decomposed non-autopsy rates over time for both language groups. Infant non-autopsy rates increased from 38.6 to 56.2 per 100 for Francophones, and from 41.2 to 57.2 per 100 for Anglophones, between 1989-1995 and 2008-2013. Trends in English-speakers were driven by socioeconomically disadvantaged Anglophones, and were accelerated by a larger proportion of deaths in this group over time. For French-speakers, rates increased in all socioeconomic groups. The increase in non-autopsy rates was larger at early neonatal ages for both languages. These findings suggest that disadvantaged Anglophones are less likely to use infant autopsy over time, and that rates can be improved by targeting early neonatal deaths.

Association of Race/Ethnicity With Very Preterm Neonatal Morbidities.

Importance: Severe morbidity in very preterm infants is associated with profound clinical implications on development and life-course health. However, studies of racial/ethnic disparities in severe neonatal morbidities are scant and suggest that these disparities are modest or null, which may be an underestimation resulting from the analytic approach used. Objective: To estimate racial/ethnic differences in severe morbidities among very preterm infants. Design, Setting, and Participants: This population-based retrospective cohort study was conducted in New York City, New York, using linked birth certificate, mortality data, and hospital discharge data from January 1, 2010, through December 31, 2014. Infants born before 24 weeks' gestation, with congenital anomalies, and with missing data were excluded. Racial/ethnic disparities in very preterm birth morbidities were estimated through 2 approaches, conventional analysis and fetuses-at-risk analysis. The conventional analysis used log-binomial regression to estimate the relative risk of 4 severe neonatal morbidities for the racial/ethnic groups. For the fetuses-at-risk analysis, Cox proportional hazards regression with death as competing risk was used to estimate subhazard ratios associating race/ethnicity with each outcome. Estimates were adjusted for sociodemographic factors and maternal morbidities. Data were analyzed from September 5, 2017, to May 21, 2018. Main Outcomes and Measures: Four morbidity outcomes were defined using International Classification of Diseases, Ninth Revision, diagnosis and procedure codes: necrotizing enterocolitis, intraventricular hemorrhage, bronchopulmonary dysplasia, and retinopathy of prematurity. Results: In total, 582 297 infants were included in this study. Of these infants, 285 006 were female (48.9%) and 297 291 were male (51.0%). Using the conventional approach in the very preterm birth subcohort, black compared with white infants had an increased risk of only bronchopulmonary dysplasia (adjusted risk ratio [aRR], 1.34; 95% CI, 1.09-1.64) and a borderline increased risk of necrotizing enterocolitis (aRR, 1.39; 95% CI, 1.00-1.93). Hispanic infants had a borderline increased risk of necrotizing enterocolitis (aRR, 1.39; 95% CI, 0.98-1.96), and Asian infants had an increased risk of retinopathy of prematurity (aRR, 1.85; 95% CI, 1.15-2.97). In the fetuses-at-risk analysis, black infants had a 4.40 times higher rate of necrotizing enterocolitis (95% CI, 2.98-6.51), a 2.73 times higher rate of intraventricular hemorrhage (95% CI, 1.63-4.57), a 4.43 times higher rate of bronchopulmonary dysplasia (95% CI, 2.88-6.81), and a 2.98 times higher rate of retinopathy of prematurity (95% CI, 2.01-4.40). Hispanic infants had an approximately 2 times higher rate for all outcomes, and Asian infants had increased risk only for retinopathy of prematurity (adjusted hazard ratio, 2.43; 95% CI, 1.43-4.11). Conclusions and Relevance: In this study, racial/ethnic disparities in neonatal morbidities among very preterm infants appear to be sizable, but may have been underestimated in previous studies, and may have implications for the future. Understanding these racial/ethnic disparities is important, as they may contribute to inequalities in health and development later in the child's life.

Linguistic mortality gradients in Quebec and the role of migrant composition.

OBJECTIVE: Anglophones and Allophones in Quebec (Canada) have lower mortality than Francophones, despite being linguistic minorities. This study assesses whether (1) language is a risk factor for mortality after accounting for migrant composition and (2) interprovincial migrants differ in mortality with respect to Quebec-born individuals. METHODS: We analyzed death records between 2004 and 2008 from Quebec (all-cause and main causes) and population data from the 2006 census to estimate age-adjusted mortality rates according to language and migrant status. Risk ratios by language and migrant status, adjusted for age, sex, and socioeconomic status, were estimated using Poisson generalized estimating equations. RESULTS: Francophone Quebec-borns had the highest mortality. Among Quebec-borns, Anglophones [RR= 0.85, 95% CI (0.79-0.91)] and Allophones [RR = 0.16, 95 %CI (0.12-0.22)] had lower mortality relative to Francophones. Interprovincial migrants had lower mortality (Anglophones [RR = 0.58, 95% CI (0.53-0.63)], Francophones [RR = 0.55, 95% CI (0.50-0.60)]) relative to Francophone Quebec-borns (Allophones were excluded due to small sample size). Among immigrants, mortality was lower for Francophones [RR = 0.62, 95% CI (0.57-0.67] and Allophones [RR = 0.35, 95% CI (0.31-0.38], but not Anglophones [RR = 0.92, 95% CI (0.84-1.01)], relative to Francophone Quebec-borns. CONCLUSION: In Quebec, linguistic disparities in mortality remained after accounting for migrant status, and both Francophone and Anglophone interprovincial migrants in Quebec had lower mortality than Quebec-born Francophones. Public health initiatives to reduce linguistic disparities in health should account for migrant status.

Quantile regression analysis of language and interpregnancy interval in Quebec, Canada. / Analyse de régression quantile de la relation entre la langue et l'intervalle entre les grossesses au Québec (Canada).

INTRODUCTION: Short and long interpregnancy intervals are associated with adverse perinatal outcomes such as miscarriage and preterm delivery, but cultural differences in interpregnancy intervals are understudied. Identifying cultural inequality in interpregnancy intervals is necessary to improve maternal-child outcomes. We assessed interpregnancy intervals for Anglophones and Francophones in Quebec. METHODS: We obtained birth records for all infants born in Quebec, 1989-2011. We identified 571 461 women with at least two births, and determined the interpregnancy interval. We defined short interpregnancy intervals (< 18 months) as the 20th percentile of the distribution, and long intervals (≥ 60 months) as the 80th percentile. Using quantile regression, we evaluated the association of language with short and long intervals, adjusted for maternal characteristics. We assessed differences over time and by maternal age for disadvantaged groups defined as no high school diploma, rural residence, and material deprivation. RESULTS: In adjusted regression models, Anglophones who had no high school diploma had intervals that were 1.0 month (95% CI: -1.5 to -0.4) shorter than Francophones at the 20th percentile of the distribution, and 1.9 months (-0.5 to 4.3) longer at the 80th percentile. Results were similar for Anglophones in rural and materially deprived areas. The trends persisted over time, but were stronger for women < 30 years. There were no differences between advantaged Anglophones and Francophones. CONCLUSION: Disadvantaged Anglophones are more likely to have short and long interpregnancy intervals relative to Francophones in Quebec. Public health interventions to improve perinatal health should target suboptimal intervals among disadvantaged Anglophones.

INTRODUCTION: On sait que les intervalles courts comme les intervalles longs entre les grossesses sont associés à des issues périnatales défavorables, comme des fausses couches et des accouchements prématurés, mais les différences culturelles à ce sujet sont mal connues. Repérer les inégalités culturelles dans les intervalles entre les grossesses est nécessaire afin d'améliorer les résultats relatifs à la santé de la mère et de l'enfant. Nous avons ainsi évalué les intervalles entre les grossesses chez les anglophones et les francophones du Québec. MÉTHODOLOGIE: Nous avons obtenu les dossiers de naissance de tous les enfants nés au Québec entre 1989 et 2011. Nous avons recensé 571 461 femmes ayant eu au moins deux naissances et déterminé l'intervalle entre leurs grossesses. Les intervalles courts entre les grossesses (moins de 18 mois) ont été définis comme étant le 20e percentile de la distribution, et les intervalles longs (60 mois ou plus), comme le 80e percentile. À l'aide de régressions quantiles, nous avons évalué l'association entre la langue et les intervalles courts et longs, ajustés en fonction des caractéristiques de la mère. Nous avons évalué les différences au fil du temps et selon l'âge de la mère pour les groupes défavorisés, qui ont été définis par l'absence de diplôme d'études secondaires, la résidence en milieu rural et le fait de vivre dans un quartier défavorisé matériellement. RÉSULTATS: Dans les modèles de régression ajustés, les anglophones sans diplôme d'études secondaires avaient des intervalles plus courts de 1,0 mois (intervalle de confiance [IC] à 95 % : −1,5 à −0,4) par rapport à leurs homologues francophones au 20e percentile de la distribution et plus longs de 1,9 mois (−0,5 à 4,3) au 80e percentile. Les résultats étaient similaires pour les anglophones des régions rurales et des quartiers matériellement défavorisés. Les tendances se sont maintenues au fil du temps, et se sont révélées plus fortes chez les femmes de moins de 30 ans. Aucune différence n'a été relevée entre les francophones favorisées et les anglophones favorisées. CONCLUSION: Au Québec, les anglophones défavorisées étaient plus susceptibles d'avoir des intervalles courts ou des longs entre leurs grossesses que les francophones défavorisées. Les interventions de santé publique visant à améliorer la santé périnatale devraient donc cibler les intervalles sous-optimaux chez les anglophones défavorisées de la province.

Health-Promoting Home and Workplace Neighborhoods: Associations With Multiple Facets of Men's Health.

Despite the importance of healthy settings for health promotion, little is known about how neighborhood characteristics affect men's health. The present study aims to explore the associations between perceptions of home and workplace neighborhoods with diverse health outcomes, and to examine mediating mechanisms. A sample of 669 men members of labor unions in Quebec, Canada, completed a questionnaire assessing social and physical aspects of their work and home neighborhoods (the Health-Promoting Neighborhood Questionnaire) as well as subjective and objective health outcomes (perceived health, positive mental health, body mass index) and potential mediators (health behaviors, self-efficacy). Structural equation modeling (path analysis) revealed that the Health-Promoting Neighborhood Questionnaire was associated with all three health outcomes, either directly or indirectly through health behaviors and self-efficacy. Both home and workplace neighborhoods were associated with men's health, home neighborhood being more strongly associated. The findings suggest that physical and social aspects of neighborhood might contribute to men's health. The study highlights positive environmental levers for urban planners, policy makers, and health professionals to promote men's health.

Peer Positive Social Control and Men's Health-Promoting Behaviors.

Men are generally thought to be less inclined to take care of their health. To date, most studies about men's health have focused on deficits in self-care and difficulties in dealing with this sphere of their life. The present study reframes this perspective, using a salutogenic strengths-based approach and seeking to identify variables that influence men to take care of their health, rather than neglect it. This study focuses on the association between peer positive social control and men's health behaviors, while controlling for other important individual and social determinants (sociodemographic characteristics, health self-efficacy, home neighborhood, spousal positive social control, and the restrictive emotionality norm). In a mixed-method study, 669 men answered a self-reported questionnaire, and interviews were conducted with a maximum variation sample of 31 men. Quantitative results indicated that, even after controlling for sociodemographic variables and other important factors, peer positive social control was significantly associated with the six health behaviors measured in the study (health responsibility, nutrition, physical activity, interpersonal relations, stress management, and spirituality). Interview results revealed that peer positive social control influenced men's health behaviors through three different mechanisms: shared activity, being inspired, and serving as a positive role model for others. In summary, friends and coworkers could play a significant role in promoting various health behaviors among adult men in their daily life. Encouraging men to socialize and discuss health, and capitalizing on healthy men as role models appear to be effective ways to influence health behavior adoption among this specific population.

Identifying emerging reproductive vulnerability: an approach to decompose differences in total fertility.

PURPOSE: We introduce a method to partition the difference in total fertility between two groups. METHODS: We computed the total fertility rate for Francophones and Anglophones of Quebec, Canada, between 1989-1993 and 2004-2008. We partitioned the difference in excess fertility for one group relative to the other into the number of children contributed by maternal age, origin, material deprivation, education, and offspring birth order. We calculated the change in total fertility over time and the factors that contributed. RESULTS: The total fertility rate was higher by 0.18 children for Francophones in 1989-1993, but the gap reversed in 2004-2008, with total fertility higher for Anglophones by 0.12 children. Francophones had higher fertility in 1989-1993 due mainly to women who were Canadian born, aged 15-29 years, without secondary diploma, or living in socioeconomic deprivation. The reversal in 2004-2008 was caused by a reduction in fertility for Francophones aged 15-29 years and an increase in the contribution of Anglophones who were foreign born, aged 30-49 years or socioeconomically disadvantaged. CONCLUSIONS: Through decomposition of differences in total fertility, we identified populations with emerging reproductive vulnerability in a large Canadian province. Socioeconomically disadvantaged Anglophones in Quebec have increasing fertility, a potential sign of increasing reproductive risk.

Inequality in Fetal Autopsy in Canada.

PURPOSE: Inequality in use of fetal autopsy is poorly understood, despite the importance of autopsy in establishing the cause of stillbirth for future prevention. We examined fetal autopsy rates between linguistic minorities in Quebec, Canada, and assessed trends over three decades. METHODS: Using registry data on 11,992 stillbirths from 1981-2011, we calculated fetal autopsy rates for Francophones, Anglophones, and Allophones by decade. RESULTS: We found lower fetal autopsy rates for Allophones (54.4%) than Francophones (68.5%) and Anglophones (63.4%), but rates decreased over time for all language groups. After 2000, Allophones had 25% higher risk of non-autopsy relative to Francophones, with 8.8 fewer autopsies for every 100 stillbirths. Allophones who were not autopsied had 32% higher risk of having an undetermined cause of death. CONCLUSION: Inequality in use of fetal autopsy may be widespread for minorities in Canada. Efforts to decrease stillbirth in minorities may require policies to increase autopsy rates.

A Difference-in-Differences Approach to Assess the Effect of a Heat Action Plan on Heat-Related Mortality, and Differences in Effectiveness According to Sex, Age, and Socioeconomic Status (Montreal, Quebec).

BACKGROUND: The impact of heat waves on mortality and health inequalities is well documented. Very few studies have assessed the effectiveness of heat action plans (HAPs) on health, and none has used quasi-experimental methods to estimate causal effects of such programs. OBJECTIVES: We developed a quasi-experimental method to estimate the causal effects associated with HAPs that allows the identification of heterogeneity across subpopulations, and to apply this method specifically to the case of the Montreal (Quebec, Canada) HAP. METHODS: A difference-in-differences approach was undertaken using Montreal death registry data for the summers of 2000-2007 to assess the effectiveness of the Montreal HAP, implemented in 2004, on mortality. To study equity in the effect of HAP implementation, we assessed whether the program effects were heterogeneous across sex (male vs. female), age (≥ 65 years vs. < 65 years), and neighborhood education levels (first vs. third tertile). We conducted sensitivity analyses to assess the validity of the estimated causal effect of the HAP program. RESULTS: We found evidence that the HAP contributed to reducing mortality on hot days, and that the mortality reduction attributable to the program was greater for elderly people and people living in low-education neighborhoods. CONCLUSION: These findings show promise for programs aimed at reducing the impact of extreme temperatures and health inequities. We propose a new quasi-experimental approach that can be easily applied to evaluate the impact of any program or intervention triggered when daily thresholds are reached. Citation: Benmarhnia T, Bailey Z, Kaiser D, Auger N, King N, Kaufman J. 2016. A difference-in-differences approach to assess the effect of a heat action plan on heat-related mortality, and differences in effectiveness according to sex, age, and socioeconomic status (Montreal, Quebec). Environ Health Perspect 124:1694-1699; http://dx.doi.org/10.1289/EHP203.

Language and unintentional injury mortality in Quebec, Canada.

Language-based differences in unintentional injury are poorly understood, despite the importance of language as a determinant of health. This study assessed inequalities in unintentional injury mortality between Francophones and Anglophones of Quebec, Canada. We calculated age-standardised rates of death by period, region, residential deprivation and cause of injury, and estimated rate ratios for Francophones relative to Anglophones. Francophones had higher unintentional injury mortality rates than Anglophones. Inequalities decreased over time for men, but rates remained 50% higher for Francophones at the end of the study period. Rates were stable for women, but were 30% higher for Francophones compared with Anglophones. Inequalities were larger at age 15-44 years, in urban areas, and for MVCs. Better understanding of risk factors for MVCs may benefit injury prevention in Quebec. Language-based differences in injury mortality warrant attention in other multilingual populations, especially across different demographic, temporal, regional and cause-of-injury groups.

Disparities and Trends in Birth Outcomes, Perinatal and Infant Mortality in Aboriginal vs. Non-Aboriginal Populations: A Population-Based Study in Quebec, Canada 1996-2010.

BACKGROUND: Aboriginal populations are at substantially higher risks of adverse birth outcomes, perinatal and infant mortality than their non-Aboriginal counterparts even in developed countries including Australia, U.S. and Canada. There is a lack of data on recent trends in Canada. METHODS: We conducted a population-based retrospective cohort study (n = 254,410) using the linked vital events registry databases for singleton births in Quebec 1996-2010. Aboriginal (First Nations, Inuit) births were identified by mother tongue, place of residence and Indian Registration System membership. Outcomes included preterm birth, small-for-gestational-age, large-for-gestational-age, low birth weight, high birth weight, stillbirth, neonatal death, postneonatal death, perinatal death and infant death. RESULTS: Perinatal and infant mortality rates were 1.47 and 1.80 times higher in First Nations (10.1 and 7.3 per 1000, respectively), and 2.37 and 4.46 times higher in Inuit (16.3 and 18.1 per 1000, respectively) relative to non-Aboriginal (6.9 and 4.1 per 1000, respectively) births (all p<0.001). Compared to non-Aboriginal births, preterm birth rates were persistently (1.7-1.8 times) higher in Inuit, large-for-gestational-age birth rates were persistently (2.7-3.0 times) higher in First Nations births over the study period. Between 1996-2000 and 2006-2010, as compared to non-Aboriginal infants, the relative risk disparities increased for infant mortality (from 4.10 to 5.19 times) in Inuit, and for postneonatal mortality in Inuit (from 6.97 to 12.33 times) or First Nations (from 3.76 to 4.25 times) infants. Adjusting for maternal characteristics (age, marital status, parity, education and rural vs. urban residence) attenuated the risk differences, but significantly elevated risks remained in both Inuit and First Nations births for the risks of perinatal mortality (1.70 and 1.28 times, respectively), infant mortality (3.66 and 1.47 times, respectively) and postneonatal mortality (6.01 and 2.28 times, respectively) in Inuit and First Nations infants (all p<0.001). CONCLUSIONS: Aboriginal vs. non-Aboriginal disparities in adverse birth outcomes, perinatal and infant mortality are persistent or worsening over the recent decade in Quebec, strongly suggesting the needs for interventions to improve perinatal and infant health in Aboriginal populations, and for monitoring the trends in other regions in Canada.

The impact of smoke-free legislation on educational differences in birth outcomes.

BACKGROUND: Smoke-free legislation may have positive effects on birth outcomes. Given that smoking and secondhand smoke during pregnancy vary with socioeconomic position, legislation may have greater effects in some socioeconomic groups. For this study, we evaluated the impact of a 2006 ban on smoking in public places in the Canadian province of Quebec on preterm birth, small-for-gestational-age birth and birth weight, and on educational differences in these birth outcomes. METHODS: We analysed data on singleton births in Quebec between 2003 and 2010. Logistic regression was used to model the association of smoke-free legislation with preterm birth (<37 weeks), very preterm birth (<34 weeks), small-for-gestational-age birth (<10th centile for gestational age and sex), low birth weight (<2500 g) and mean birth weight, adjusting for secular trends before and after legislation. Interaction terms were included to assess differential effects by level of maternal education. RESULTS: Smoke-free legislation was associated with average reductions of 3.1 preterm births (95% CI 0.1 to 6.0), 2.3 very preterm births (95% CI 0.9 to 3.7), 5.9 small-for-gestational-age births (95% CI 2.6 to 9.3) and 1.0 low birthweight infants (95% CI 0.4 to 1.6) per 1000 live births, as well as a 17.1 g increase in mean birth weight (95% CI 10.7 to 23.6). Legislation was associated with improved birth outcomes in all categories of maternal education. CONCLUSIONS: Smoke-free legislation in Quebec was associated with reductions in preterm and small-for-gestational-age births, and an increase in birth weight. There was no compelling evidence that legislation impacted educational gradients in birth outcomes.

Mortality inequality in populations with equal life expectancy: Arriaga's decomposition method in SAS, Stata, and Excel.

PURPOSE: Life expectancy is used to measure population health, but large differences in mortality can be masked even when there is no life expectancy gap. We demonstrate how Arriaga's decomposition method can be used to assess inequality in mortality between populations with near equal life expectancy. METHODS: We calculated life expectancy at birth for Quebec and the rest of Canada from 2005 to 2009 using life tables and partitioned the gap between both populations into age and cause-specific components using Arriaga's method. RESULTS: The life expectancy gap between Quebec and Canada was negligible (<0.1 years). Decomposition of the gap showed that higher lung cancer mortality in Quebec was offset by cardiovascular mortality in the rest of Canada, resulting in identical life expectancy in both groups. Lung cancer in Quebec had a greater impact at early ages, whereas cardiovascular mortality in Canada had a greater impact at older ages. CONCLUSIONS: Despite the absence of a gap, we demonstrate using decomposition analyses how lung cancer at early ages lowered life expectancy in Quebec, whereas cardiovascular causes at older ages lowered life expectancy in Canada. We provide SAS/Stata code and an Excel spreadsheeet to facilitate application of Arriaga's method to other settings.

Constructing inverse probability weights for continuous exposures: a comparison of methods.

Inverse probability-weighted marginal structural models with binary exposures are common in epidemiology. Constructing inverse probability weights for a continuous exposure can be complicated by the presence of outliers, and the need to identify a parametric form for the exposure and account for nonconstant exposure variance. We explored the performance of various methods to construct inverse probability weights for continuous exposures using Monte Carlo simulation. We generated two continuous exposures and binary outcomes using data sampled from a large empirical cohort. The first exposure followed a normal distribution with homoscedastic variance. The second exposure followed a contaminated Poisson distribution, with heteroscedastic variance equal to the conditional mean. We assessed six methods to construct inverse probability weights using: a normal distribution, a normal distribution with heteroscedastic variance, a truncated normal distribution with heteroscedastic variance, a gamma distribution, a t distribution (1, 3, and 5 degrees of freedom), and a quantile binning approach (based on 10, 15, and 20 exposure categories). We estimated the marginal odds ratio for a single-unit increase in each simulated exposure in a regression model weighted by the inverse probability weights constructed using each approach, and then computed the bias and mean squared error for each method. For the homoscedastic exposure, the standard normal, gamma, and quantile binning approaches performed best. For the heteroscedastic exposure, the quantile binning, gamma, and heteroscedastic normal approaches performed best. Our results suggest that the quantile binning approach is a simple and versatile way to construct inverse probability weights for continuous exposures.

Neighbourhood income and neonatal, postneonatal and sudden infant death syndrome (SIDS) mortality in Canada, 1991-2005.

BACKGROUND: Rates of infant mortality declined in Canada in the 1990s and 2000s, but the extent to which all socio-economic levels benefitted from this progress is unknown. OBJECTIVES: This study investigated differences and time trends in neonatal, postneonatal and sudden infant death syndrome (SIDS) mortality across neighbourhood income quintiles among live births in Canada from 1991 through 2005. METHODS: The Canadian linked live birth and infant death file was used, excluding births from Ontario, Yukon, Northwest Territories and Nunavut. Mortality rates for neonatal, postneonatal and sudden infant death syndrome (SIDS) were calculated by neighbourhood income quintile and period (1991-1995, 1996-2000, 2001-2005). Hazard ratios (HR) for neighbourhood income quintile and period were computed, adjusting for province of residence, maternal age, parity, infant sex and multiple birth. RESULTS: In urban areas, for the entire study period (1991-2005), the poorest neighbourhood income quintile had a higher hazard of neonatal death (adjusted HR 1.24, 95% CI 1.15-1.34), postneonatal death (adjusted HR 1.58, 95% CI 1.41-1.76) and SIDS (adjusted HR 1.83, 95% CI 1.49-2.26) compared to the richest quintile. Postneonatal and SIDS mortality rates declined by 37% and 57%, respectively, between 1991-1995 and 2001-2005 whereas no significant change was observed in neonatal mortality. The decrease in postneonatal and SIDS mortality rates occurred across all income quintiles. CONCLUSION: This study shows that despite a decrease in infant mortality and SIDS across all neighbourhood income quintiles over time in Canada, socio-economic inequalities persist. This finding highlights the need for effective infant health promotion strategies in vulnerable populations.