Housing conditions and respiratory hospitalizations among First Nations people in Canada.

BACKGROUND: Respiratory diseases are among the leading causes of acute care hospitalization for First Nations people. Poor housing conditions are associated with respiratory disorders and may be related to the likelihood of hospitalization. This analysis examines whether First Nations identity is associated with higher odds of hospitalization for respiratory conditions relative to non-Aboriginal persons, and whether such differences in hospitalization rates remain after consideration of housing conditions. DATA AND METHODS: Data from the 2006 Census linked to the Discharge Abstract Database were used to analyze differences in hospitalization for respiratory tract infections and asthma between First Nations and non-Aboriginal people when housing conditions were taken into account. RESULTS: Rural on-reserve First Nations people were more likely than non-Aboriginal people to be hospitalized for a respiratory tract infection (1.5% versus 0.5%) or for asthma (0.2% versus 0.1%). For respiratory tract infection hospitalizations, adjustment for housing conditions, household income and residential location reduced differences, but the odds remained nearly three times higher for on-reserve First Nations people (OR = 2.83; CI: 2.69 to 2.99) and two times higher for off-reserve First Nations people (OR = 2.03; CI: 1.87 to 2.21), compared with the non-Aboriginal cohort. For asthma hospitalizations, adjustment for household income reduced the odds more than did adjustment for housing conditions. Even with full adjustment, the odds of asthma hospitalization relative to non-Aboriginal people remained significantly higher for First Nations people. INTERPRETATION: First Nations people are significantly more likely than non-Aboriginal people to be hospitalized for respiratory tract infections and asthma, even when housing conditions, household income and residential location are taken into account. While housing conditions are associated with such hospitalizations, household income may be more important.

Hospitalization for ambulatory care sensitive conditions among urban Métis adults.

BACKGROUND: Hospitalizations for ambulatory care sensitive conditions (ACSCs) are potentially preventable, but may be required if these conditions are not managed well. National-level information about ACSC hospitalizations is available for Canada, but not for Aboriginal groups. This study describes ACSC hospitalizations among urban Métis adults relative to their non-Aboriginal counterparts. DATA AND METHODS: The 2006/2007-to-2008/2009 Discharge Abstract Database, which contains hospitalization records from all acute care facilities (excluding Quebec), was linked to the 2006 Census to obtain Aboriginal identity information. Age-standardized ACSC hospitalization rates (ASHRs) per 100,000 population and rate ratios were calculated for Métis aged 18 to 74 relative to non-Aboriginal people of the same ages. Odds of ACSC hospitalizations were estimated using logistic regression models, adjusting for demographic, geographic, and socioeconomic characteristics. RESULTS: The ASHR for ACSCs among urban Métis adults was twice that among non-Aboriginal adults (393 versus 184 per 100,000 population). Even when demographic, geographic, and socioeconomic characteristics were taken into account, Métis had higher odds of ACSC hospitalizations overall (OR 1.5). Most commonly, these hospitalizations were for diabetes (OR 1.8) or chronic obstructive pulmonary disease (OR 1.5). Modelled factors partly reduced differences between Métis and non-Aboriginal adults, but variations between the groups remained after all adjustments. INTERPRETATION: Rates of ACSC hospitalizations were higher among Métis than among non-Aboriginal adults who lived in urban areas. Further research using other data sources is warranted to assess the roles of factors not available for this analysis, such as primary care, co-morbidity, and health behaviours.

Rates of cancer incidence across terciles of the foreign-born population in Canada from 2001-2006.

OBJECTIVES: To address the issue of comparative risk of cancer in Canada's immigrant population, an area-based methodology was applied to examine whether or not estimated cancer incidence rates among individuals living in given areas vary systematically according to the concentration of foreign-born individuals living in the same area. This method provides an alternative, accessible surveillance method in the absence of linked individual-level information to extend the work of others by providing both national and subnational standardized, hence comparable, results to address this issue. METHODS: Canadian Cancer Registry data (2001 to 2006) and 2006 Census data provided dissemination area information regarding the concentration of the foreign-born population and population estimates for rate denominators. Cancer (all cause and cause-specific) incidence rate ratios (age-standardized and by age/sex) were calculated by foreign-born concentration areas at both national and regional levels. RESULTS: An inverse gradient was identified between cancer incidence rates and area concentration of foreign-born, with the all-sites cancer rate ranging from a low of 388 per 100,000 among individuals living in areas with a high concentration of foreign-born to a high of 493 per 100,000 among individuals living in areas with a low concentration of foreign-born. This pattern occurred nationally for lung, colorectal, prostate and female breast cancers. However, for liver, nasopharynx, and thyroid cancers, higher cancer rates were observed in areas with a higher versus lower concentration of foreign-born populations. CONCLUSION: The study findings provide suggestive evidence of decreased cancer risk among foreign-born populations for most cancers except nasopharynx, liver and thyroid for which risks were higher. The results of this study demonstrate the value of ecological-based methods for disease surveillance in the absence of individual-level information on immigrant status in the national cancer registry.

Geozones: an area-based method for analysis of health outcomes.

BACKGROUND: Administrative datasets often lack information about individual characteristics such as Aboriginal identity and income. However, these datasets frequently contain individual-level geographic information (such as postal codes). This paper explains the methodology for creating Geozones, which are area-based thresholds of population characteristics derived from census data, which can be used in the analysis of social or economic differences in health and health service utilization. DATA AND METHODS: With aggregate 2006 Census information at the Dissemination Area level, population concentration and exposure for characteristics of interest are analysed using threshold tables and concentration curves. Examples are presented for the Aboriginal population and for income gradients. RESULTS: The patterns of concentration of First Nations people, Métis, and Inuit differ from those of non-Aboriginal people and between urban and rural areas. The spatial patterns of concentration and exposure by income gradients also differ. INTERPRETATION: The Geozones method is a relatively easy way of identifying areas with lower and higher concentrations of subgroups. Because it is ecological-based, Geozones has the inherent strengths and weaknesses of this approach.

Cancer patterns in Inuit Nunangat: 1998-2007.

OBJECTIVES: To compare cancer incidence patterns between residents of Inuit Nunangat and the rest of Canada. STUDY DESIGN: Cancer cases were geographically linked to either Inuit Nunangat or the rest of Canada using postal codes or other geographic information. Population estimates were derived from the 2001 and 2006 censuses. METHODS: Cancer cases were combined from 1998 to 2007 for Inuit Nunangat and the rest of Canada. Age-standardised incidence rates were calculated for all site cancers and sub-sites by sex. Standardised rate ratios between these 2 areas were calculated for all site cancers and sub-sites. RESULTS: The age-standardised incidence rate for all cancer sites (1998-2007) was 14% lower for the Inuit Nunangat male population and 29% higher for the female population by comparison to the rest of Canada. Cancers of the nasopharynx, lung and bronchus, colorectal, stomach (males), and kidney and renal pelvis (females), were elevated in the Inuit Nunangat population compared to the rest of Canada, whereas prostate and female breast cancers were lower in the Inuit Nunangat population. CONCLUSIONS: Cancers with potentially modifiable risk factors, such as buccal cavity and pharynx, nasopharynx, lung and bronchus, and colorectal cancer were elevated in the Inuit Nunangat population compared to the rest of Canada. Besides greater smoking prevalence within Inuit Nunangat by comparison to the rest of Canada, distinct socioeconomic characteristics between respective area populations including housing, and income may have contributed to incidence differentials. This study demonstrated that a geographic approach can be used in cancer surveillance when populations of interest are spatially distinguishable, and reside across distinct jurisdictions whose combined cancer registries will not completely provide information to identify the population of interest.