Screening-level assessment of cancer risk associated with ambient air exposure in Aamjiwnaang First Nation.

The manuscript reports findings from a screening-level assessment of cancer risk from outdoor air in Aamjiwnaang First Nation. Ambient air pollution can contribute to cardiovascular/respiratory diseases, and certain types of cancer. Certain communities may be at higher risk to the negative health impacts due to their geographical proximity to pollution sources. Outdoor air concentrations were mapped and the Lifetime Excess Cancer Risks (LECR) associated with long-term exposure to known carcinogens were estimated. LECR results for both benzene and 1,3-butadiene were above one per million. The LECR for benzene was 6.4 per million when the Health Canada slope factor was applied and 12.0 when using the US EPA. For 1,3-butadiene the LECR estimate was 8.8 per million. This work provides a better understanding of environmental exposures and potential associated cancer risks for residents in the Aamjiwnaang community and highlights the need for further air monitoring and a more detailed risk assessment.

Measuring the impact of the COVID-19 pandemic on organized cancer screening and diagnostic follow-up care in Ontario, Canada: A provincial, population-based study.

It is essential to quantify the impacts of the COVID-19 pandemic on cancer screening, including for vulnerable sub-populations, to inform the development of evidence-based, targeted pandemic recovery strategies. We undertook a population-based retrospective observational study in Ontario, Canada to assess the impact of the pandemic on organized cancer screening and diagnostic services, and assess whether patterns of cancer screening service use and diagnostic delay differ across population sub-groups during the pandemic. Provincial health databases were used to identify age-eligible individuals who participated in one or more of Ontario's breast, cervical, colorectal, and lung cancer screening programs from January 1, 2019-December 31, 2020. Ontario's screening programs delivered 951,000 (-41%) fewer screening tests in 2020 than in 2019 and volumes for most programs remained more than 20% below historical levels by the end of 2020. A smaller percentage of cervical screening participants were older (50-59 and 60-69 years) during the pandemic when compared with 2019. Individuals in the oldest age groups and in lower-income neighborhoods were significantly more likely to experience diagnostic delay following an abnormal breast, cervical, or colorectal cancer screening test during the pandemic, and individuals with a high probability of living on a First Nation reserve were significantly more likely to experience diagnostic delay following an abnormal fecal test. Ongoing monitoring and management of backlogs must continue. Further evaluation is required to identify populations for whom access to cancer screening and diagnostic care has been disproportionately impacted and quantify impacts of these service disruptions on cancer incidence, stage, and mortality. This information is critical to pandemic recovery efforts that are aimed at achieving equitable and timely access to cancer screening-related care.

Cancer in First Nations people in Ontario, Canada: Incidence and mortality, 1991 to 2010.

BACKGROUND: This study aims to measure cancer incidence and mortality rates of Registered First Nations people in Ontario and compare them with those of other people in Ontario from 1991 to 2010. DATA AND METHODS: The federal Indian Register, the Ontario Cancer Registry and the Registered Persons Database were linked to develop a cohort of First Nations people diagnosed with cancer in Ontario. Sex-and site-specific age-standardized cancer incidence and mortality rates, and selected trends over time, were calculated. Rate ratios (RRs) were used to compare rates in First Nations peoples with those of other people in Ontario. RESULTS: The First Nations cohort comprised 194,392 people, with 6,859 cancer diagnoses. First Nations people had higher rates for certain cancers than others in Ontario: lung (males RR 1.19; females RR 1.47), colorectal (males RR 1.36; females RR 1.34) and kidney (males RR1.95; females RR 2.23). While lung cancer rates rose in First Nations females (annual percent change [APC] +2.67), they fell at a similar rate (APC -2.28) in males. Cervical cancer rates fell (APC -9.53) and approached the rate among other females in Ontario. Kidney cancer rates increased in First Nations people. DISCUSSION: First Nations people in Ontario have higher incidence and mortality for certain cancers compared with other people in Ontario. However, the declines in cervical cancer rates in First Nations females and lung cancer rates in First Nations males illustrate the likely impact of Pap test uptake and smoking cessation programs. Community-led efforts to develop culturally appropriate prevention and screening programs are essential to further reduce cancer rates in First Nations people.

Housing conditions and adverse birth outcomes among Indigenous people in Canada.

OBJECTIVES: Poor housing conditions and household crowding have been identified as important health concerns for Indigenous populations in many countries but have not been explored in relation to adverse birth outcomes in these populations. We investigated housing conditions and adverse birth outcomes in a nationally representative sample of Indigenous people in Canada. METHODS: Data were from a cohort of births between May 2004 and May 2006 created by linking birth and infant death registration data with the 2006 Canadian census. Log-binomial regression was used to examine associations between housing variables (persons per room and needed household repairs) and three adverse birth outcomes: preterm birth (PTB), small-for-gestational-age (SGA) birth, and infant mortality. Separate regression models were run for First Nations, Métis and Inuit mothers, with adjustment for parity and parental socio-economic variables. RESULTS: Need for major household repairs was associated with a slightly increased risk of PTB among First Nations and Métis mothers (adjusted RRs 1.12 and 1.13, respectively; 95% CI 0.94-1.34 and 0.89-1.44, respectively) and a moderately increased risk of infant death in all three groups (aRR = 1.69, 95% CI 1.00-2.85). Household crowding was also associated with a slightly elevated risk of PTB in all three groups (aRR = 1.10, 95% CI 0.95-1.29) and with an increased risk of infant mortality among First Nations (aRR = 1.57, 95% CI 0.97-2.53). CONCLUSION: This study highlights the need to improve understanding of links between housing conditions and perinatal health outcomes in Indigenous populations, including examining cause-specific infant mortality in relation to housing characteristics.

RéSUMé: OBJECTIF: Les mauvaises conditions de logement et le surpeuplement ont été identifiés dans plusieurs pays comme étant des enjeux importants de santé chez les populations autochtones. Cependant, aucune étude n'a exploré les conditions de logement en lien avec les issues défavorables de la grossesse dans ces populations. C'est ce que nous avons examiné dans une cohorte de naissances de mères autochtones au Canada, représentative à l'échelle nationale. MéTHODES: Nous avons analysé une cohorte de naissances survenues entre mai 2004 et mai 2006. Cette cohorte a été créée en couplant les données d'enregistrement des naissances et des décès avec les données du Recensement du Canada de 2006. Nous avons utilisé une régression binomiale logarithmique pour estimer les associations entre les conditions de logement (nombre de personnes par chambre et besoins de réparation du logement) et les taux de trois issues défavorables de la grossesse (naissance prématurée, les nouveau-nés petits pour l'âge gestationnel et la mortalité infantile). Des modèles séparés ont été construits pour les femmes des Premières Nations, inuites et métisses, en ajustant les analyses pour la parité et les variables socioéconomiques parentales. RéSULTATS: Les besoins de réparation du logement ont été associés avec un risque ajusté légèrement augmenté de naissance prématurée parmi les mères des Premières Nations et métisses (RRs ajustés : 1,12 et 1,13, respectivement; IC de 95 % : 0,94, 1,34 et 0,89, 1,44, respectivement) et avec un risque modérément élevé de la mortalité infantile dans les trois groupes (RRa = 1,69, IC de 95 % : 1,00, 2,85). Le surpeuplement du logement a été associé avec un risque légèrement augmenté de la naissance prématurée dans les trois groupes (RRa = 1,10, IC de 95 % : 0,95, 1,29) et avec un risque élevé de la mortalité infantile parmi les Premières Nations (RRa = 1,57, IC de 95 % : 0,97, 2,53). CONCLUSION: Cette étude souligne le besoin d'améliorer notre connaissance des liens entre les conditions du logement et les issues de la santé périnatale au sein des populations autochtones, y compris l'étude de la mortalité infantile par cause en association avec les conditions de logement.

Experiences of Inuit in Canada who travel from remote settings for cancer care and impacts on decision making.

BACKGROUND: Inuit experience the highest cancer mortality rates from lung cancer in the world with increasing rates of other cancers in addition to other significant health burdens. Inuit who live in remote areas must often travel thousands of kilometers to large urban centres in southern Canada and negotiate complex and sometimes unwelcoming health care systems. There is an urgent need to improve Inuit access to and use of health care. Our study objective was to understand the experiences of Inuit in Canada who travel from a remote to an urban setting for cancer care, and the impacts on their opportunities to participate in decisions during their journey to receive cancer care. METHODS: We are an interdisciplinary team of Steering Committee and researcher partners ("the team") from Inuit-led and/or -specific organizations that span Nunavut and the Ontario cancer health systems. Guided by Inuit societal values, we used an integrated knowledge translation (KT) approach with qualitative methods. We conducted semi-structured interviews with Inuit participants and used process mapping and thematic analysis. RESULTS: We mapped the journey to receive cancer care and related the findings of client (n = 8) and medical escort (n = 6) ("participant") interviews in four themes: 1) It is hard to take part in decisions about getting health care; 2) No one explains the decisions you will need to make; 3) There is a duty to make decisions that support family and community; 4) The lack of knowledge impacts opportunities to engage in decision making. Participants described themselves as directed, with little or no support, and seeking opportunities to collaborate with others on the journey to receive cancer care. CONCLUSIONS: We describe the journey to receive cancer care as a "decision chain" which can be described as a series of events that lead to receiving cancer care. We identify points in the decision chain that could better prepare Inuit to participate in decisions related to their cancer care. We propose that there are opportunities to build further health care system capacity to support Inuit and enable their participation in decisions related to their cancer care while upholding and incorporating Inuit knowledge.

An evaluation of Indigenous Tobacco Program smoking prevention workshops with First Nations youth in Ontario, Canada.

SETTING: The Indigenous Tobacco Program (ITP) operated by the Indigenous Cancer Care Unit at Cancer Care Ontario provides customized tobacco prevention workshops to First Nations youth across Ontario, in partnership with First Nations communities and partner organizations. INTERVENTION: First Nations youth in Canada are more likely than non-Indigenous youth to be smokers. The ITP aims to address the negative health impacts of commercial tobacco, using culturally relevant approaches, tools and resources while remaining respectful to the significance of sacred tobacco. This paper aims to determine whether a culturally tailored tobacco prevention workshop increases tobacco-related knowledge among First Nations youth in Ontario. OUTCOMES: The workshops exhibited promise in impacting First Nations youth knowledge on the harms of commercial tobacco, as after the workshop intervention, all indicators showed improved knowledge. Building strong and ongoing relationships with communities and partner organizations is vital to the success of the program. IMPLICATIONS: Culturally tailored workshops grounded in traditional knowledge and values provide an opportunity to increase the knowledge of the harms of commercial tobacco among First Nations youth in Ontario. With commercial tobacco use and exposure having tremendous health consequences, such interventions are essential.

RéSUMé: CADRE: Le Programme pour la lutte contre le tabagisme chez les peuples autochtones (PLTPA) administré par l'Unité des soins de cancérologie chez les peuples autochtones à Cancer Care Ontario dispense des ateliers personnalisés de prévention du tabagisme aux jeunes Autochtones dans tout l'Ontario, en partenariat avec les communautés et organismes partenaires des Premières Nations. INTERVENTION: Les jeunes des Premières Nations canadiennes sont plus susceptibles de fumer que les jeunes non autochtones. Le PLTPA vise à remédier aux effets négatifs sur la santé du tabac commercial à l'aide d'approches, d'outils et de ressources pertinents sur le plan culturel, tout en demeurant respectueux de l'importance du tabac sacré. Cet article vise à déterminer si un atelier de prévention adapté sur le plan culturel permet d'accroître les connaissances relatives au tabac parmi les jeunes des Premières Nations de l'Ontario. RéSULTATS: Les ateliers ont eu des répercussions prometteuses sur les connaissances des jeunes des Premières Nations ayant trait aux effets néfastes du tabac commercial, puisqu'à la suite de l'atelier d'intervention, tous les indicateurs dénotaient une amélioration des connaissances à ce sujet. L'entretien de relations solides et continues avec les communautés et organismes partenaires est essentiel à la réussite du programme. IMPLICATIONS: Les ateliers culturellement adaptés et fondés sur des connaissances et des valeurs traditionnelles permettent d'accroître les connaissances des jeunes des Premières Nations ontariennes ayant trait aux effets néfastes du tabac commercial. Au vu des impacts énormes sur la santé, liés à la consommation de tabac commercial et à l'exposition à celui-ci, de telles interventions sont essentielles.

Influence of Preexisting Diabetes on Survival After a Breast Cancer Diagnosis in First Nations Women in Ontario, Canada.

PURPOSE: Survival after a breast cancer diagnosis is poorer in First Nations women with a preexisting comorbidity compared with comorbidity-free First Nations women in Ontario, Canada. Given the high prevalence of diabetes in this population, it is important to determine whether preexisting diabetes is related to poorer survival after a breast cancer diagnosis. METHODS: All First Nations women were identified from a cohort of First Nations people diagnosed with breast cancer in diagnostic periods-1995 to 1999 and 2000 to 2004-and seen at a regional cancer program (RCP) in Ontario. Preexisting diabetes status and other factors, such as age at diagnosis, body mass index, and stage at diagnosis, were collected from medical charts at the regional cancer programs. The association between preexisting diabetes and First Nations status was examined by each of the demographic, personal, tumor, and treatment factors using logistic regression models. Survival was compared between First Nations women with (n = 67) and without (n = 215) preexisting diabetes, adjusted by significant study factors using a Cox proportional hazards regression model. RESULTS: The 5-year survival rate among First Nations women with diabetes was 59.8% versus 78.7% among those without diabetes (P < .01). Preexisting diabetes significantly increased the risk of death among First Nations women with breast cancer (hazard ratio, 1.87; 95% CI, 1.12 to 3.13) after adjustment for age group, period of diagnosis, body mass index, other comorbidities at diagnosis, and stage. CONCLUSION: This study recommends awareness of this survival discrepancy among the treatment team for First Nations patients with breast cancer with preexisting diabetes.

Perinatal health among foreign versus native-born mothers in Canada: variations across outcomes and cohorts.

BACKGROUND: To examine perinatal health differences between foreign-born and native-born mothers in Canada across multiple outcomes and two cohorts 10 years apart. METHODS: Using 94 896 and 131 271 births in the 1996 and 2006 Canadian Census-Birth Cohort, respectively, we estimated risk ratios and risk differences of preterm birth (PTB), small-for-gestational age (SGA), large-for-gestational age (LGA), stillbirth and infant mortality between foreign-born and Canadian-born mothers. RESULTS: In the 1996 cohort, we observed no important differences in adverse outcomes between foreign-born and native-born mothers. In the 2006 cohort, however, foreign-born mothers had lower risks of PTB, LGA, stillbirth, and infant mortality and a higher risk of SGA on both the relative and absolute scales. Lowered risk of PTB among foreign-born mothers in the 2006 cohort was also observed within Caucasian, East Asian, Southeast Asian and South Asian mothers. Favourable outcomes associated with foreign-born status in the 2006 cohort were negatively graded by duration of residence in Canada among immigrant mothers. CONCLUSIONS: Differences in perinatal health by maternal foreign-born status varied across cohorts and a more pronounced 'healthy migrant' effect was observed among more recent migrants. The native-born mothers' perinatal health over time and a more restrictive/selective immigration policy in recent years would explain our results.

Adverse birth outcomes and infant mortality according to registered First Nations status and First Nations community residence across Canada.

OBJECTIVE: Studies of perinatal health outcomes in Canadian First Nations populations have largely focused on limited geographical areas and have been unable to examine outcomes by registered status and community residence. In this study, we compare rates of adverse birth outcomes among First Nations individuals living within vs. outside of First Nations communities and those with vs. without registered status. METHODS: Data included 13,506 singleton pregnancies from the 2006 Canadian Birth-Census Cohort. Outcomes examined included preterm birth (PTB), small- and large-for-gestational-age birth (SGA, LGA), stillbirth, overall infant mortality, and neonatal and postneonatal mortality. Risk ratios (RRs) were estimated with adjustment for maternal age, education, parity, and paternal education. RESULTS: Mothers living in First Nations communities and those with status had elevated adjusted risks of LGA (RR for First Nations community residence = 1.22, 95% CI = 1.09-1.35; RR for status = 1.50, 95% CI = 1.16-1.93). Rates of SGA were significantly lower among mothers with status (adjusted RR = 0.62, 95% CI = 0.44-0.86). Rates of PTB did not vary substantially by residence or by status. Adjusted differences in fatal outcomes could not be estimated, owing to small cell sizes. However, mothers living in First Nations communities had higher crude rates of infant mortality (10.9 vs. 7.7 per 1000), particularly for neonatal mortality (6.1 vs. 2.9). CONCLUSION: Future investigations should explore risk factors, including food security and access to health care services, that may explain disparities in SGA and LGA by status and residence within First Nations populations.

Adverse birth outcomes in relation to maternal marital and cohabitation status in Canada.

PURPOSE: An increasing percentage of children are born to couples who cohabit but are not legally married. Using data from a nationally representative Canadian sample, we estimated associations of maternal marital and cohabitation status with stillbirth, infant mortality, preterm birth (PTB), and small- and large-for-gestational-age (SGA and LGA) birth. METHODS: The 2006 Canadian Birth-Census Cohort was created by linking birth registration data with the 2006 long-form census. We used log-binomial regression to estimate risk ratios (RRs) for adverse birth outcomes associated with being single or living with a common-law partner. Analyses were adjusted for maternal age and education. RESULTS: Data were analyzed for 130,931 singleton births. Adjusted RRs (95% confidence intervals) for single mothers compared with married mothers were 1.92 (1.51-2.42) for stillbirth, 2.08 (1.55-2.81) for infant mortality, 1.36 (1.27-1.46) for PTB, 1.31 (1.22-1.39) for SGA birth, and 0.95 (0.90-1.01) for LGA birth. Adjusted RRs for cohabiting mothers compared with married mothers were 0.93 (0.74-1.16) for stillbirth, 1.05 (0.81-1.35) for infant mortality, 1.09 (1.03-1.15) for PTB, 1.05 (0.99-1.10) for SGA birth, and 0.96 (0.92-1.00) for LGA birth. CONCLUSIONS: In a nationally representative Canadian birth cohort, cohabiting and legally married women experienced similar birth outcomes, but most outcomes for single women were substantially worse.

Birth outcomes among First Nations, Inuit and Métis populations.

BACKGROUND: First Nations, Inuit, and Métis are at higher risk of adverse birth outcomes than are non-Indigenous people. However, relatively little perinatal information is available at the national level for Indigenous people overall or for specific identity groups. DATA AND METHODS: This analysis describes and compares rates of preterm birth, small-for-gestational-age birth, large-for-gestational-age birth, stillbirth, and infant mortality (neonatal, postneonatal, and cause-specific) in a nationally representative sample of First Nations, Inuit, Métis, and non-Indigenous births. The study cohort consisted of 17,547 births to Indigenous mothers and 112,112 births to non-Indigenous mothers from 2004 through 2006. The cohort was created by linking the Canadian Live Birth, Infant Death and Stillbirth Database to the long form of the 2006 Census, which contains a self-reported Indigenous identifier. RESULTS: With the exception of small-for-gestational-age birth, adverse birth outcomes occurred more frequently among First Nations, Inuit, and Métis women than among non-Indigenous women. Inuit had the highest preterm birth rate (11.4 per 100 births; 95% CI: 9.7 to 13.1) among the three Indigenous groups. The large-for-gestational-age rate was highest for First Nations births (20.9 per 100 births; 95% CI: 19.9 to 21.8). Infant mortality rates were more than twice as high for each Indigenous group compared with the non-Indigenous population, and rates of sudden infant death syndrome were more than seven times higher among First Nations and Inuit. DISCUSSION: The results confirm disparities in birth outcomes between Indigenous and non-Indigenous populations, and demonstrate differences among First Nations, Métis and Inuit.

Paternal education and adverse birth outcomes in Canada.

BACKGROUND: Research on predictors of adverse birth outcomes has focused on maternal characteristics. Much less is known about the role of paternal factors. Paternal education is an important socioeconomic marker that may predict birth outcomes over and above maternal socioeconomic indicators. METHODS: Using data from the 2006 Canadian Birth-Census Cohort, we estimated the associations between paternal education and preterm birth, small-for-gestational-age (SGA) birth, stillbirth and infant mortality in Canada, controlling for maternal characteristics. Binomial regression was used to estimate risk ratios and risk differences for adverse birth outcomes associated with paternal education, after controlling for maternal education, age, marital status, parity, ethnicity and nativity. RESULTS: A total of 131 285 singleton births were included in the present study. Comparing the lowest to the highest paternal education category, adjusted risk ratios (95% CIs) were 1.22 (1.10 to 1.35) for preterm birth, 1.13 (1.03 to 1.23) for SGA birth, 1.92 (1.28 to 2.86) for stillbirth and 1.67 (1.01 to 2.75) for infant mortality. Consistent patterns of associations were observed for absolute risk differences. CONCLUSIONS: Our study suggests that low paternal education increases the risk of adverse birth outcomes, and especially of fetal and infant mortality, independently from maternal characteristics.

Missing paternal data and adverse birth outcomes in Canada.

BACKGROUND: Research on predictors of birth outcomes tends to focus on maternal characteristics. Less is known about the role of paternal factors. Missing paternal data on administrative records may be a marker for risk of adverse birth outcomes. DATA AND METHODS: Analyses were performed on a cohort of births that occurred from May 16, 2004 through May 15, 2006, which was created by linking birth and death registration data with the 2006 Canadian census. Log-binomial and binomial regression were used to estimate relative risks and risk differences for preterm birth, small-for-gestational-age birth, stillbirth and infant mortality associated with the absence of paternal information. Analyses controlled for maternal age, education, household income, parity, marital status, ethnicity and birthplace. RESULTS: The analyses pertained to 135,285 singleton births. Paternal data were missing from the birth registration for 7,461 births (4.6%) and from the census data for 17,713 births (11.4%). The adjusted relative risks associated with missing paternal data on the birth registration were 1.12 (95% CI: 0.99, 1.26) for preterm birth; 1.15 (1.05, 1.26) for small-for-gestational-age birth; 1.86 (1.27, 2.73) for stillbirth; and 1.53 (1.00, 2.34) for infant mortality. Estimates were robust to varying definitions of missing paternal information, based on the birth registration, census data, or both. INTERPRETATION: This study suggests that missing paternal data is a marker for increased risk of adverse birth outcomes, over and above maternal characteristics.

The 2006 Canadian Birth-Census Cohort.

BACKGROUND: Evidence on socioeconomic and ethnocultural disparities in perinatal health in Canada tends to be limited to analyses by neighbourhood or for selected provinces. In 2010, the Canadian Institutes of Health Research awarded funding for a project on perinatal outcomes. This article describes the resulting 2006 Canadian Birth-Census Cohort Database. DATA AND METHODS: From the Canadian Live Birth, Infant Death and Stillbirth Database, 687,340 records of children born in Canada from May 16, 2004 through May 15, 2006 to mothers whose usual place of residence was Canada were selected as in-scope births. Deterministic rules were applied to link each person on the birth record-child, mother, father-to 2006 Census data.The cohort was restricted to records linked to a long-form questionnaire, and a cohort weight was developed. Cohort rates (unweighted and weighted) for five birth outcomes-preterm birth, small-for-gestational age, large-for-gestational age, stillbirth, and infant mortality-were compared with rates for all in-scope births across birth characteristics. Cohort rates for these birth outcomes were examined across selected census characteristics. RESULTS: Linkage rates were 91% for births surviving to age 1, 76% for stillbirths, and 80% for infant deaths matched to a birth registration. The cohort estimates were similar to those for all in-scope births, particularly after the cohort weight was applied. The cohort data produced plausible estimates of selected birth outcomes across maternal ethnocultural categories and levels of education. INTERPRETATION: The 2006 Canadian Birth-Census Cohort data can help inform perinatal surveillance and research in Canada.

Comparison of black-white disparities in preterm birth between Canada and the United States.

BACKGROUND: A higher risk of preterm birth among black women than among white women is well established in the United States. We compared differences in preterm birth between non-Hispanic black and white women in Canada and the US, hypothesizing that disparities would be less extreme in Canada given the different historical experiences of black populations and Canada's universal health care system. METHODS: Using data on singleton live births in Canada and the US for 2004-2006, we estimated crude and adjusted risk ratios and risk differences in preterm birth (< 37 wk) and very preterm birth (< 32 wk) among non-Hispanic black versus non-Hispanic white women in each country. Adjusted models for the US were standardized to the covariate distribution of the Canadian cohort. RESULTS: In Canada, 8.9% and 5.9% of infants born to black and white mothers, respectively, were preterm; the corresponding figures in the US were 12.7% and 8.0%. Crude risk ratios for preterm birth among black women relative to white women were 1.49 (95% confidence interval [CI] 1.32 to 1.66) in Canada and 1.57 (95% CI 1.56 to 1.58) in the US (p value for heterogeneity [pH] = 0.3). The crude risk differences for preterm birth were 2.94 (95% CI 1.91 to 3.96) in Canada and 4.63 (95% CI 4.56 to 4.70) in the US (pH = 0.003). Adjusted risk ratios for preterm birth (pH = 0.1) were slightly higher in Canada than in the US, whereas adjusted risk differences were similar in both countries. Similar patterns were observed for racial disparities in very preterm birth. INTERPRETATION: Relative disparities in preterm birth and very preterm birth between non-Hispanic black and white women were similar in magnitude in Canada and the US. Absolute disparities were smaller in Canada, which reflects a lower overall risk of preterm birth in Canada than in the US in both black and white populations.

Cancer survival among First Nations people of Ontario, Canada (1968-2007).

We aimed to compare cancer survival in Ontario First Nations people to that in other Ontarians for five major cancer types: colorectal, lung, cervix, breast and prostate. A list of registered or "Status" Indians in Ontario was used to create a cohort of over 140,000 Ontario First Nations people. Cancers diagnosed in cohort members between 1968 and 2001 were identified from the Ontario Cancer Registry, with follow-up for death until December 31st, 2007. Flexible parametric modeling of the hazard function was used to compare the survival experience of the cohort to that of other Ontarians. We considered changes in survival from the first half of the time period (1968-1991) to the second half (1992-2001). For other Ontarians, survival had improved over time for every cancer site. For the First Nations cohort, survival improved only for breast and prostate cancers; it either declined or remained unchanged for the other cancers. For cancers diagnosed in 1992 or later, all-cause and cause-specific survival was significantly poorer for First Nations people diagnosed with breast, prostate, cervical, colorectal (male and female) and male lung cancers as compared to their non-First Nations peers. For female lung cancer, First Nations women appeared to have poorer survival; however, the result was not statistically significant. Ontario's First Nations population experiences poorer cancer survival when compared to other Ontarians and strategies to reduce these inequalities must be developed and implemented.

Are residents of downtown Toronto influenced by their urban neighbourhoods? Using concept mapping to examine neighbourhood characteristics and their perceived impact on self-rated mental well-being.

BACKGROUND: There is ample evidence that residential neighbourhoods can influence mental well-being (MWB), with most studies relying on census or similar data to characterize communities. Few studies have actively investigated local residents' perceptions. METHODS: Concept mapping was conducted with residents from five Toronto neighbourhoods representing low income and non-low income socio-economic groups. These residents participated in small groups and attended two sessions per neighbourhood. The first session (brainstorming) generated neighbourhood characteristics that residents felt influenced their MWB. A few weeks later, participants returned to sort these neighbourhood characteristics and rate their relative importance in affecting residents' 'good' and 'poor' MWB. The data from the sorting and rating groups were analyzed to generate conceptual maps of neighbourhood characteristics that influence MWB. RESULTS: While agreement existed on factors influencing poor MWB (regardless of neighbourhood, income, gender and age), perceptions related to factors affecting good MWB were more varied. For example, women were more likely to rank physical beauty of their neighbourhood and range of services available as more important to good MWB, while men were more likely to cite free access to computers/internet and neighbourhood reputation as important. Low-income residents emphasized aesthetic attributes and public transportation as important to good MWB, while non-low-income residents rated crime, negative neighbourhood environment and social concerns as more important contributors to good MWB. CONCLUSION: These findings contribute to the emerging literature on neighbourhoods and MWB, and inform urban planning in a Canadian context.

A decade of research in Inuit children, youth, and maternal health in Canada: areas of concentrations and scarcities.

Inuit Canadians are on average about 20 years younger and have a 10-year lower life expectancy than other Canadians. While there have been improvements in Inuit health status over time, significant health disparities still remain. This paper will review the peer-reviewed literature related to Inuit child, youth, and maternal health between 2000 and 2010, investigate which thematic areas were examined, and determine what proportion of the research is related to each group. Establishing areas of research concentrations and scarcities may help direct future research where it is needed. We followed a systematic literature review and employed peer-reviewed research literature on child, youth, and maternal health which were selected from 3 sources, MEDLINE, CINAHL, and the Circumpolar Health Bibliographic Database. The resulting references were read, and summarized according to population group and thematic area. The thematic areas that emerged by frequency were: infectious disease; environment/environmental exposures; nutrition; birth outcomes; tobacco; chronic disease; health care; policy, human resources; interventions/programming; social determinants of health; mental health and wellbeing; genetics; injury; and dental health. The 72 papers that met the inclusion criteria were not mutually exclusive with respect to group studied. Fifty-nine papers (82%) concerned child health, 24 papers (33%) youth health, and 58 papers (81%) maternal health. The review documented high incidences of illness and significant public health problems; however, in the context of these issues, opportunities to develop research that could directly enhance health outcomes are explored.

Favourable prognostic factors of subsequent screen-detected breast cancers among women aged 50-69.

Most studies reporting more favourable biological features of screen-detected breast cancers compared with symptomatic or interval cancers include initial or prevalent screens and therefore may not indicate the real benefit of screening on breast cancer mortality. We conducted case-case comparisons within a cohort of eligible women (N=771 715) who were aged 50-69 between 1 January 1995 and 31 December 2003. A randomly selected sample of breast cancers (N=1848) diagnosed among these women were compared by detection method. Tumour characteristics of interval cancers (N=362) diagnosed after 6-24 months of a negative screen or symptomatic breast cancers (N=491) were compared with subsequent screen-detected breast cancers diagnosed within 6 months of a positive screen (N=995) using polytomous logistic regression. Tumours were evaluated for clinical presentation, histology and expression of hormone receptors. Women with symptomatic detected [odds ratio (OR)=7.48, 95% confidence interval (CI)=5.38-10.38] and interval cancers (OR=2.20, 95% CI=1.56-3.10) were more often diagnosed at stage III-IV versus I than women with rescreen-detected cancers. After adjusting for tumour size, women with symptomatic cancers had tumours of higher grade (OR=1.50, 95% CI=1.05-2.15) and mitotic score (OR=1.69, 95% CI=1.15-2.49) and women with interval cancers had tumours of higher mitotic score (OR=1.52, 95% CI=1.01-2.28) compared with women diagnosed at screening. Subsequent screen-detected cancers are not only detected at an earlier stage but are also less aggressive, leading to a better prognosis. As long-term mortality reduction for breast screening may depend on subsequent screens, our study indicates that mammography screening can be effective in women aged 50-69.

Stage at diagnosis and comorbidity influence breast cancer survival in First Nations women in Ontario, Canada.

BACKGROUND: Indigenous populations in Canada and abroad have poorer survival after a breast cancer diagnosis compared with their geographic counterparts; however, the influence of many demographic, personal, tumor, and treatment factors has not been examined to describe this disparity according to stage at diagnosis. METHODS: A case-case design was employed to compare First Nations (FN) women (n = 287) to a frequency-matched random sample of non-FN women (n = 671) diagnosed with breast cancer within the Ontario Cancer Registry. Women were matched on period of diagnosis (1995-1999 and 2000-2004), age at diagnosis (<50 vs. ≥50), and Regional Cancer Centre (RCC). Stage and other factors were collected from medical charts at the RCCs. Survival was compared using an adjusted Cox proportional hazards model and stratified by stage at diagnosis (I, II, and III-IV). Determinants of survival in FN women stratified by stage at diagnosis were also modeled. RESULTS: Survival was more than three times poorer for FN women diagnosed at stage I than for non-FN women (HR = 3.10, 95% CI = 1.39-6.88). The risk of death after a stage I breast cancer diagnosis was about five times higher among FN women with a comorbidity other than diabetes (HR = 4.65, 95% CI = 1.39-15.53) and was more than five times greater for women with diabetes (HR = 5.49, 95% CI = 1.69-17.90) than for those without a comorbidity. CONCLUSIONS: Having a preexisting comorbidity was the most important factor in explaining the observed survival disparity among FN women. IMPACT: Improving the general health status of FN women could increase their survival after an early-stage breast cancer diagnosis.