Assessing the "healthy immigrant effect" in mental health: Intra- and inter-cohort trends in mood and/or anxiety disorders.

BACKGROUND: The healthy immigrant effect implies that, at the time of immigration, new immigrants are typically healthier than the Canadian-born population. Furthermore, this health advantage fades the longer cohorts of immigrants remain in the host country. METHODS: Most studies assessing the healthy immigrant effect rely on strong, untestable assumptions to extract unique effects for length of stay (LOS) (i.e., how long an immigrant has been in a host country), period (i.e., year of observation), and cohort (i.e., year of immigration). Rather than attempting to parse out separate effects for LOS, period, and cohort, we adopt a descriptive, cohort-centric approach to study immigrant mental health, which examines intra- and inter-cohort trends, that is, joint LOS-period and cohort-period parameters, respectively. While intra-cohort trends show how immigrants' mental health change with LOS across periods, inter-cohort trends reveal how the mental health of successive cohorts of immigrants differ across time periods. To provide a thorough assessment of the healthy immigrant effect, we use both survey and administrative data on cohorts of Canadian immigrants from 2003 to 2013. RESULTS: The survey data reveal that mental health declines steeply (i.e., there is an increase in mood and/or anxiety disorders) within and across immigrant cohorts, while the administrative data show little overall change in mental health care utilization within and across cohorts. The divergent results may reflect issues related to barriers in access to mental health services because the administrative data, which are based on health care utilization, do not the capture the increase in mental disorders seen in the survey data. CONCLUSION: This study highlights the benefit of a cohort-based approach to assess the healthy immigrant effect as it pertains to mental health as well as the importance of using different types of data, which may be measuring different aspects of immigrant mental health and health care utilization.

Comparison of socio-economic determinants of COVID-19 testing and positivity in Canada: A multi-provincial analysis.

BACKGROUND: The effects of the COVID-19 pandemic have been more pronounced for socially disadvantaged populations. We sought to determine how access to SARS-CoV-2 testing and the likelihood of testing positive for COVID-19 were associated with demographic factors, socioeconomic status (SES) and social determinants of health (SDH) in three Canadian provinces. METHODS: An observational population-based cross-sectional study was conducted for the provinces of Ontario, Manitoba and New Brunswick between March 1, 2020 and April 27, 2021, using provincial health administrative data. After excluding residents of long-term care homes, those without current provincial health insurance and those who were tested for COVID-19 out of province, records from provincial healthcare administrative databases were reviewed for 16,900,661 healthcare users. Data was modelled separately for each province in accordance to a prespecified protocol and follow-up consultations among provincial statisticians and collaborators. We employed univariate and multivariate regression models to examine determinants of testing and test results. RESULTS: After adjustment for other variables, female sex and urban residency were positively associated with testing, while female sex was negatively associated with test positivity. In New Brunswick and Ontario, individuals living in higher income areas were more likely to be tested, whereas in Manitoba higher income was negatively associated with both testing and positivity. High ethnocultural composition was associated with lower testing rates. Both high ethnocultural composition and high situational vulnerability increased the odds of testing positive for SARS-CoV-2. DISCUSSION: We observed that multiple demographic, income and SDH factors were associated with SARS-CoV-2 testing and test positivity. Barriers to healthcare access identified in this study specifically relate to COVID-19 testing but may reflect broader inequities for certain at-risk groups.

Socioeconomic Status Among Cochlear Implant Candidates and Association With Surgical Pursuance.

Importance: Despite the sizeable global burden of hearing loss, cochlear implants have poor penetrance among eligible hearing-impaired individuals. Identifying populations who may benefit from a cochlear implant but among whom penetrance is poor is an important aim in reducing the health-related and economic effects of hearing loss on both individuals and society. Objectives: To explore the association of socioeconomic status (SES) with cochlear implant candidacy and the decision to undergo cochlear implantation. Design, Setting, and Participants: This retrospective cohort study was performed in a tertiary academic center. All adult patients evaluated for cochlear implant candidacy from January 1, 1999, through December 31, 2022, were included in the analysis. Exposures: Household income quintile and rural or urban residence were used as proxies for SES based on zip code linkage to US Census and US Department of Agriculture data. Main Outcomes and Measures: Odds of cochlear implant candidacy and surgery. Results: A total of 754 individuals underwent candidacy evaluations and were included in the analysis (386 [51.2%] women; mean [SD] age, 64.0 [15.7] years). Of these, 693 (91.9%) were cochlear implant candidates, and 623 candidates (89.9%) underwent cochlear implantation. Multivariable analyses demonstrated that individuals in the highest income quintile had lower odds of cochlear implant candidacy compared with those in the lowest income quintile (odds ratio [OR], 0.26 [95% CI, 0.08-0.91]), and candidates in the highest income quintile had greater odds of undergoing cochlear implant surgery compared with those in the lowest quintile (OR, 2.59 [95% CI, 1.14-5.86]). Living in a small town or a micropolitan or rural area was associated with lower odds of undergoing cochlear implant surgery compared with living in a metropolitan core (OR, 0.18 [95% CI, 0.04-0.83]) after controlling for distance to the primary implant center. Conclusions and Relevance: The findings of this cohort study suggest that individuals with higher SES are less likely to qualify for a cochlear implant; however, those who qualify are more likely to undergo surgery compared with those with lower SES. These findings highlight a hearing health care disparity that should be addressed through further studies to guide population-based initiatives.

Essential requirements for the governance and management of data trusts, data repositories, and other data collaborations.

Introduction: Around the world, many organisations are working on ways to increase the use, sharing, and reuse of person-level data for research, evaluation, planning, and innovation while ensuring that data are secure and privacy is protected. As a contribution to broader efforts to improve data governance and management, in 2020 members of our team published 12 minimum specification essential requirements (min specs) to provide practical guidance for organisations establishing or operating data trusts and other forms of data infrastructure. Approach and Aims: We convened an international team, consisting mostly of participants from Canada and the United States of America, to test and refine the original 12 min specs. Twenty-three (23) data-focused organisations and initiatives recorded the various ways they address the min specs. Sub-teams analysed the results, used the findings to make improvements to the min specs, and identified materials to support organisations/initiatives in addressing the min specs. Results: Analyses and discussion led to an updated set of 15 min specs covering five categories: one min spec for Legal, five for Governance, four for Management, two for Data Users, and three for Stakeholder & Public Engagement. Multiple changes were made to make the min specs language more technically complete and precise. The updated set of 15 min specs has been integrated into a Canadian national standard that, to our knowledge, is the first to include requirements for public engagement and Indigenous Data Sovereignty. Conclusions: The testing and refinement of the min specs led to significant additions and improvements. The min specs helped the 23 organisations/initiatives involved in this project communicate and compare how they achieve responsible and trustworthy data governance and management. By extension, the min specs, and the Canadian national standard based on them, are likely to be useful for other data-focused organisations and initiatives.

Mapping Canadian Data Assets to Generate Real-World Evidence: Lessons Learned from Canadian Real-World Evidence for Value of Cancer Drugs (CanREValue) Collaboration's RWE Data Working Group.

Canadian provinces routinely collect patient-level data for administrative purposes. These real-world data (RWD) can be used to generate real-world evidence (RWE) to inform clinical care and healthcare policy. The CanREValue Collaboration is developing a framework for the use of RWE in cancer drug funding decisions. A Data Working Group (WG) was established to identify data assets across Canada for generating RWE of oncology drugs. The mapping exercise was conducted using an iterative scan with informant surveys and teleconference. Data experts from ten provinces convened for a total of three teleconferences and two in-person meetings from March 2018 to September 2019. Following each meeting, surveys were developed and shared with the data experts which focused on identifying databases and data elements, as well as a feasibility assessment of conducting RWE studies using existing data elements and resources. Survey responses were compiled into an interim data report, which was used for public stakeholder consultation. The feedback from the public consultation was used to update the interim data report. We found that databases required to conduct real-world studies are often held by multiple different data custodians. Ninety-seven databases were identified across Canada. Provinces held on average 9 distinct databases (range: 8-11). An Essential RWD Table was compiled that contains data elements that are necessary, at a minimal, to conduct an RWE study. An Expanded RWD Table that contains a more comprehensive list of potentially relevant data elements was also compiled and the availabilities of these data elements were mapped. While most provinces have data on patient demographics (e.g., age, sex) and cancer-related variables (e.g., morphology, topography), the availability and linkability of data on cancer treatment, clinical characteristics (e.g., morphology and topography), and drug costs vary among provinces. Based on current resources, data availability, and access processes, data experts in most provinces noted that more than 12 months would be required to complete an RWE study. The CanREValue Collaboration's Data WG identified key data holdings, access considerations, as well as gaps in oncology treatment-specific data. This data catalogue can be used to facilitate future oncology-specific RWE analyses across Canada.

Linking national immigration data to provincial repositories: The case of Canada.

BACKGROUND: Canadian health data repositories link datasets at the provincial level, based on their residents' registrations to provincial health insurance plans. Linking national datasets with provincial health care registries poses several challenges that may result in misclassification and impact the estimation of linkage rates. A recent linkage of a federal immigration database in the province of Manitoba illustrates these challenges. OBJECTIVES: a) To describe the linkage of the federal Immigration, Refugees and Citizenship Canada Permanent Resident (IRCC-PR) database with the Manitoba healthcare registry and b) compare data linkage methods and rates between four Canadian provinces accounting for interprovincial mobility of immigrants. METHODS: We compared linkage rates by immigrant's province of intended destination (province vs. rest of Canada). We used external nationwide immigrant tax filing records to approximate actual settlement and obtain linkage rates corrected for interprovincial mobility. RESULTS: The immigrant linkage rates in Manitoba before and after accounting for interprovincial mobility were 84.8% and 96.1, respectively. Linkage rates did not substantially differ according to immigrants' characteristics, with a few exceptions. Observed linkage rates across the four provinces ranged from 74.0% to 86.7%. After correction for interprovincial mobility, the estimated linkage rates increased > 10 percentage points for the provinces that stratified by intended destination (British Columbia and Manitoba) and decreased up to 18 percentage points for provinces that could not use immigration records of those who did not intend to settle in the province (New Brunswick and Ontario). CONCLUSIONS: Despite variations in methodology, provincial linkage rates were relatively high. The use of a national immigration dataset for linkage to provincial repositories allows a more comprehensive linkage than that of province-specific subsets. Observed linkage rates can be biased downwards by interprovincial migration, and methods that use external data sources can contribute to assessing potential selection bias and misclassification.

Socioeconomic Status and Melanoma in Canada: A Systematic Review.

As melanoma is one of the leading cancers in average years of life lost per death from disease, screening and early diagnosis are imperative to decrease morbidity and mortality. Socioeconomic status (SES) has been shown to be associated with melanoma incidence. However, it is unclear if this association holds true in universal healthcare systems where screening, diagnostic, and treatment services are available to all patients. The objective of this systematic review was to evaluate the evidence on the association of SES and melanoma incidence in Canada. A comprehensive search of PubMed and EMBASE yielded 7 studies reporting on melanoma incidence or outcomes with respect to SES in Canada. High SES was associated with increased melanoma incidence across all studies, which encompassed all Canadian provinces, and time periods spanning from 1979 to 2012. Studies also reported an increasing incidence of melanoma over time. There were substantial discrepancies in melanoma incidence across Canadian provinces, after controlling for SES and demographic characteristics. Populations of lower SES and living within certain healthcare regions had increased risks of advanced melanoma at diagnosis. This review highlights the potential for inequities in access to care even within a universal healthcare system. Future research is needed to characterize specific risk factors within different patient groups and within the universal health system context in order to implement targeted strategies to lower melanoma incidence, morbidity, and mortality.

An examination of the association between lifetime history of prostate and pancreatic cancer diagnosis and occupation in a population sample of Canadians.

BACKGROUND: Occupation was assessed as possible risk factors for prostate (PCa) and pancreatic cancer in a large Canadian worker cohort. METHODS: The Canadian Census Health and Environment Cohort (CanCHEC) was derived from linking the 1991 Canadian Census Cohort to the Canadian Cancer Database (1969-2010), Canadian Mortality Database (1991-2011), and Tax Summary Files (1981-2011). From the total sample of 1,931,110 persons, we identified and derived two samples of 28,610 men and 3,220 men and women with a past history of PCa and pancreatic cancer diagnoses, respectively. Cox proportional hazards models were used to estimate hazards ratios and 95% confidence intervals for occupation. RESULTS: In Canadian men aged 24-64 years, the highest elevated risks of PCa were observed for library clerks (HR = 2.36, 95% CI:1.12-4.97), medical radiation technologists (HR = 1.66, 95% CI:1.04-2.65), telecommunications and line cable workers (HR = 1.62, 95% CI: 1.22-3.16) and commissioned police officers (HR = 1.54, 95% CI: 1.10-2.16. The highest elevated risk for pancreatic cancer were observed for commissioned police officers (HR = 4.34, 95% CI: 1.85-10.21), photographic and film processors (HR = 3.97, 95% CI:1.69-9.34), railway and motor transport labourers (HR = 3.94, 95% CI: 1.67-9.29), and computer engineers (HR = 3.82, 95%CI: 1.52-9.61). CONCLUSION: These findings emphasize the need for further study of job-related exposures and the potential influence of non-occupational factors such as screening practices.

The SPOR-Canadian Data Platform: a national initiative to facilitate data rich multi-jurisdictional research.

Administrative health data is recognized for its value for conducting population-based research that has contributed to numerous improvements in health. In Canada, each province and territory is responsible for administering its own publicly funded health care program, which has resulted in multiple sets of administrative health data. Challenges to using these data within each of these jurisdictions have been identified, which are further amplified when the research involves more than one jurisdiction. The benefits to conducting multi-jurisdictional studies has been recognized by the Canadian Institutes of Health Research (CIHR), which issued a call in 2017 for proposals that address the challenges. The grant led to the creation of Health Data Research Network Canada (HDRN), with a vision is to establish a distributed network that facilitates and accelerates multi-jurisdictional research in Canada. HDRN received funding for seven years that will be used to support the objectives and activities of an initiative called the Strategy for Patient-Oriented Research Canadian Data Platform (SPOR-CDP). In this paper, we describe the challenges that researchers face while using, or considering using, administrative health data to conduct multi-jurisdictional research and the various ways that the SPOR-CDP will attempt to address them. Our objective is to assist other groups facing similar challenges associated with undertaking multi-jurisdictional research.

Does Socioeconomic Status Affect Stage at Presentation for Larynx Cancer in Canada's Universal Health Care System?

OBJECTIVE: Diagnosis of laryngeal cancer is dependent on awareness that persistent hoarseness needs to be investigated as well as access to an otolaryngologist. This study aimed to better classify and understand 3 factors that may lead to variability in stage at presentation of laryngeal cancer: (1) socioeconomic status (SES), (2) differences in access to health care by location of residence (rural vs urban or by province), and (3) access to an otolaryngologist (by otolaryngologists per capita). STUDY DESIGN: Registry-based multicenter cohort analysis. SETTING: This was a national study across Canada, a country with a single-payer, universal health care system. SUBJECTS: All persons 18 years or older who were diagnosed with laryngeal cancer from 2005 to 2013 inclusive were extracted from the Canadian Cancer Registry (CCR). METHODS: Ordered logistic regression was used to determine the effect of income, age, sex, province of residence, and rural vs urban residence on stage at presentation. RESULTS: A total of 1550 cases were included (1280 males and 265 females). The stage at presentation was earlier in the highest income quintile (quintile 5) compared to the lower income quintiles (quintiles 1-4) (odds ratio [OR], 0.68; P < .05). There was a statistically significant difference in stage at presentation based on rural or urban residence within the highest income quintile (OR, 1.73; P < .005). CONCLUSION: There is a relationship between SES and stage at presentation for laryngeal cancer even in the Canadian universal health care system.

Participation and retention in the breast cancer screening program in New Brunswick Canada.

New Brunswick (NB) Canada uses its breast cancer screening service program to assess the extent to which eligible NB women are complying with mammography guidelines. While many studies have investigated factors associated with participation in periodic breast cancer screening in Canada and elsewhere, most work has relied on self-reported surveys or smaller scale primary data collection. Using a longitudinal administrative dataset for NB over the period 1996-2011 of 255,789 eligible women aged 45-69, this study examined demographic, socioeconomic and geographic factors associated with initial participation in regular screening at age 50 and ongoing retention in the program. Logistic regression was used to examine correlates of initial screening, while rescreening participation was estimated using survival analysis accounting for rescreening episodes. Initial screening participation was lower for women born outside of NB, many women living farther away from screening centers, women in rural areas, and higher for married women. In contrast, retention was higher for rural women and women recently arrived in NB. For both participation and retention, regional disparities across health zone persisted after controlling for observable personal and locational factors. The analysis highlights important characteristics to be targeted to increase screening but also that how health zones operate their screening programs exerts a very significant effect on the use of screening services by eligible women. This offers lessons for the design and evaluation of any cancer screening program.

Cancer and the healthy immigrant effect: a statistical analysis of cancer diagnosis using a linked Census-cancer registry administrative database.

BACKGROUND: A large volume of research has been published on both the socio economic and demographic determinants of cancer and on the health of immigrants and minority groups. Yet because of data limitations, little research examines differences in the occurrence of cancer incidence between immigrants and non-immigrants and among immigrants defined by region of birth and time in the host country. In particular it is not known whether a healthy immigrant effect is present for cancer and if so, whether this advantage is lost with additional years of residence in the host country. METHODS: This paper uses a large data file from Statistics Canada that links Census information on immigrant status, socioeconomic status including educational attainment, and other person-level information with administrative data on cancer and mortality over a continuous 13 year period of observation. It estimates discrete and continuous time duration models to identify differences in cancer diagnosis by immigrant subgroup after controlling for a variety of potential confounders. Differences in historical smoking behavior are not observable at the individual level in the dataset but are accounted for indirectly using various methods. RESULTS: Results in general confirm the existence of a healthy immigrant effect for cancer in that, overall, recent immigrants to Canada are significantly less likely than otherwise comparable non-immigrant Canadians to be diagnosed with any cancer and the most common forms of cancer by site. As well, this gap appears to decline with additional years in Canada for immigrant men and women, eventually converging to Canadian-born levels. Differentiating among immigrant subgroups by period of arrival and country of birth reveals significant variation across immigrant subgroups, with immigrant men and women from developing countries typically having a lower likelihood of being diagnosed with cancer than immigrants from the US, UK and continental Europe. As well, controlling for immigrant heterogeneity this way weakens the conclusion that the gap narrows with years in Canada. Immigrant men overall continue to exhibit convergence to Canadian-born levels for diagnosis of any cancer and for prostate cancer, while immigrant women exhibit narrowing over time only for breast cancer. Although smoking behavior is not directly observed, controlling for subgroup-specific lifetime smoking behavior using survey data has only a relatively minor effect on the estimated differences. CONCLUSIONS: The specificity of the results by cancer type, gender, immigrant status and ethnicity provides useful guidance for future research by helping to narrow the possible channels through which social and economic characteristics may be affecting cancer incidence.

Incidence of differentiated thyroid cancer in Canada by City of residence.

BACKGROUND: Thyroid cancer incidence in Canada is increased in high socioeconomic groups, and in urban compared with rural areas. The objective of this study was to analyze patterns in thyroid cancer incidence across Canada, particularly with respect to the major urban areas across the country, to identify whether there are any discrepancies in thyroid cancer incidence between Canadian cities. METHODS: Cases were drawn from the Canadian Cancer Registry. Demographic and socioeconomic information were extracted from the Canadian Census of Population data. We linked cases to income quintiles (InQs) by patients' postal codes, and categorized residence by census metropolitan area ((CMA), population >100,000). Within the Toronto CMA we further classified by census subdivision (CSD). RESULTS: There were a total of 33 CMAs across the country. After controlling for demographic and socio-economic factors, we found that the Toronto CMA had an IRR of thyroid cancer that was significantly higher than all other CMAs across the country. For 70% of CMAs and CAs across Canada, the IRR for thyroid cancer was less than half of the IRR for thyroid cancer in the Toronto CMA. As Toronto is one of the largest CMAs, we then subdivided the Toronto area into CSDs to examine how incidence of thyroid cancer varies within this large area. The Toronto City core was used as the reference category and all other areas were compared directly to it. In doing so, we found that a contiguous area of three CSDs North of Toronto had higher IRRs compared with the Toronto city core: Markham, Vaughan and Richmond Hill. CONCLUSIONS: After controlling for demographic and socioeconomic factors, we found that the Toronto CMA has the highest incidence of thyroid cancer nationwide. Several explanations could account for this discrepancy including increased detection due to increased access to imaging, differences in ethnicity or environmental exposures.

The relationship between survival and socio-economic status for head and neck cancer in Canada.

BACKGROUND: Human papilloma virus (HPV) is emerging as the primary cause for some head and neck cancers. The objective of this study was to investigate the association between head and neck cancer (HNC) survival and socioeconomic status (SES) in Canada, and to investigate changes in the relationship between HNC survival and SES from 1992 to 2005. METHODS: Cases were drawn from the Canadian Cancer Registry (1992-2005), and were categorized into three subsites: oropharynx, oral cavity, and "other" (hypopharynx, larynx, and nasopharynx). Demographic and socioeconomic information were extracted from the Canadian Census of Population data for the study period, which included three census years: 1991, 1996 and 2001. We linked cases to income quintiles (InQs) according to patients' postal codes. RESULTS: Overall survival, without controlling for smoking, for oropharyngeal cancer increased dramatically from 1992-2005 in Canada. This increase in survival for oropharynx cancer was eliminated by the introduction of controls for smoking. Survival for all head and neck cancer subsites was strongly correlated with SES, as measured by income quintile, with lower InQ's having lower survival than higher. Lastly, the magnitude of the difference in survival between the highest and lowest income quintiles increased significantly over the time period studied for oropharynx cancer, but did not statistically significantly change for oral cavity cancer or other head and neck cancers. CONCLUSIONS: These data confirm a significant impact of socioeconomic deprivation on overall survival for head and neck cancers in Canada, and may provide indirect evidence that HPV-positive head and neck cancers are more common in higher socioeconomic groups.

Is lower socioeconomic status associated with more advanced thyroid cancer stage at presentation? A study in two Canadian centers.

BACKGROUND: Some studies have shown a higher incidence of thyroid cancer in patients with insurance coverage and higher socioeconomic status (SES), and a higher thyroid cancer stage in patients with lower SES, suggesting SES-related health disparity in thyroid cancer. However, it is not known if the same is evident under a universal healthcare system such as that in Canada. METHODS: We used data from the Canadian Thyroid Cancer Consortium, a large thyroid cancer registry that collects data from two major thyroid cancer referral centers (London, Ontario, and Halifax, Nova Scotia). We included patients who presented with thyroid cancer between 1998 and 2011. We determined age at presentation, sex, and thyroid cancer status using the American Joint Committee on Cancer (AJCC) staging criteria. Individuals' postal codes were used to retrieve data from the Canadian census for the years 1996, 2001, and 2006 to approximate household income. Ordered logistic regression was used to determine odds ratios of presenting with more advanced stage thyroid cancer as they relate to income, age, and sex. RESULTS: We included 1701 patients: 1334 cases from London and 367 from Halifax. Thyroid cancer was diagnosed more frequently in the higher SES groups (p<0.001). Compared to patients in the top income quintile, patients in the lowest and second-lowest income quintiles had significantly higher odds of having more advanced stage thyroid cancer at presentation (OR 1.58, p=0.002; 1.37, p=0.024 respectively). CONCLUSIONS: Our study suggests that, similar to countries that lack a universal healthcare system, health disparity in thyroid cancer also exists in Canada. It appears that while thyroid cancers were diagnosed more frequently in Canadian patients of higher SES, Canadian patients in the lower SES groups had more advanced stage thyroid cancer at presentation.

Incidence of differentiated thyroid cancer by socioeconomic status and urban residence: Canada 1991-2006.

BACKGROUND: The incidence of thyroid cancer is increasing in Canada. The purpose of this study was to investigate the following questions. First, what was the magnitude of increased incidence of thyroid cancer in Canada from 1991-2006? Second, is there an association between socioeconomic status (SES) and thyroid cancer incidence in Canada? Third, does the relationship between SES and the incidence of thyroid cancer vary by rural/urban status? METHODS: Thyroid cancer cases were drawn from the Canadian Cancer Registry. Demographic and socioeconomic information were extracted from the Canadian Census of Population data. We linked cases to income quintiles (InQs) according to patients' postal codes, and categorized place of residence into city, town, or rural. We then performed a negative binomial regression analysis on the incidence of thyroid cancer to identify relationships between these variables. RESULTS: The overall incidence of thyroid cancer in Canada increased by 156% between 1991 and 2006. Incidence was significantly lower among individuals from lower InQs (incidence rate ratio 0.77 for lowest InQ compared to highest). The incidence of thyroid cancer was more than 25% lower in towns or rural areas compared to cities, after controlling for SES and demographic factors. Lastly, when we allowed the relationship between thyroid cancer incidence and geography of residence to vary by SES, we found that the difference in incidence between highest and lowest InQs was significantly larger in cities than in towns and was insignificant in rural areas. CONCLUSIONS: Our study confirmed a dramatic increase in thyroid cancer incidence in Canada. Thyroid cancer incidence was significantly higher in higher InQs and in cities. These data support the theory that increased access to imaging is largely responsible for this increased incidence.

Incidence of head and neck cancer and socioeconomic status in Canada from 1992 to 2007.

OBJECTIVE: To investigate the association between head and neck cancer (HNC) incidence and socioeconomic status (SES) in Canada, and investigate changes in the relationship between HNC incidence and SES from 1992 to 2007. MATERIALS AND METHODS: Cases were drawn from the Canadian Cancer Registry (1992-2007), and were categorized into three subsites: oropharynx, oral cavity, and "other" (hypopharynx, larynx, and nasopharynx). Demographic and socioeconomic information were extracted from the Canadian Census of Population data for the study period (1992-2007), which included four census years. We linked cases to income quintiles (InQs) according to patients' postal codes. RESULTS: Incidence rates in the lowest InQs were significantly higher than in the highest InQs for all HNC subsites. The incidence of oropharyngeal cancer increased over the time period 1992-2007 for all InQs. However, the greatest increase in incidence was in the highest InQs. As a result, over the time period the gap between the incidence of the highest and lowest InQs significantly narrowed for oropharyngeal cancer. For oral cavity cancer and the other head and neck cancers, the overall incidence did not increase and the gap in incidence did not change significantly. CONCLUSION: HNC incidence was higher with lower income in all HNC subsites in Canada from 1992 to 2007. The gap in incidence between the highest and the lowest InQs narrowed for oropharyngeal cancer over the time period studied, but was unchanged for the other HNC subsites.

The migration decisions of physicians in Canada: the roles of immigrant status and spousal characteristics.

Around 25% of practicing physicians in Canada are graduates of medical schools outside of Canada. These physicians are more likely to be working in rural communities, and in particular account for more than half of new physicians starting practice in rural regions. The extent to which particular health regions and provinces are able to retain their physicians is crucial if shortages in the delivery of physician and surgeon services in both the short and longer terms are to be avoided. In this paper, we use data from the confidential master files of the Canadian Census over the years 1991-2006 to study the geographic mobility of immigrant and non-immigrant physicians who are already resident in Canada. We consider both inter- and intra-provincial migration, with a particular focus on migration to and from rural areas of Canada. We exploit the fact that it is possible to link individuals within families in the Census files in order to investigate the impact on the migration decision of the characteristics of a married physician's spouse. Our results indicate that the magnitude of outflows is substantial and that the retention of immigrant physicians in rural areas and in some provinces will continue to be difficult. We find strong evidence that migration is a family decision, and spousal characteristics (education, age, years in Canada for immigrants) are important. As well, we find that large Canadian cities (mainly in Ontario) are the likely destination for the types of immigrant physicians typically able to be recruited to other areas, implying recruitment efforts of smaller provinces may have significant implications for the size of health care costs in larger provinces.

Head and neck cancer in Canada: trends 1992 to 2007.

OBJECTIVES: The objective of this study was to investigate the changes in the epidemiology (incidence, age at diagnosis, and survival) of head and neck cancers (HNCs) in Canada in the past decade. STUDY DESIGN: Analysis of a national cancer data registry. SETTING: All Canadian hospital institutions treating head and neck cancer. SUBJECTS AND METHODS: Using Canadian Cancer Registry data (1992-2007), the authors categorized HNCs into 3 groups according to their possible association with human papillomavirus (HPV): oropharynx (highly associated), oral cavity (moderate association), and "other" (hypopharynx, larynx, and nasopharynx), which are not HPV related. They calculated age-adjusted incidence, median age at diagnosis, and survival for each category. RESULTS: Oropharynx tumors increased in incidence over the study time period (annual percent change: 1.50% men, 0.8% women), whereas oral cavity tumors decreased (2.10% men, 0.4% women), as did other HNCs (decreased by 3.0% for men and 1.9% for women). The median age at diagnosis for oropharynx cancer decreased by an average of 0.23 years/y. There was no change for oral cavity tumors but an increase for other HNCs of 0.12 years/y. Survival for patients with oropharynx cancer increased by 1.5%/y but was significant for men only. Survival for patients with oral cavity and other HNCs also increased in men only by 0.9%/y and 0.25%/y, respectively. CONCLUSION: Oropharynx cancer, which is highly correlated with HPV infection, is increasing in incidence in Canada, with a decreasing age at diagnosis and an improvement in survival. This could have implications for screening strategies and treatment for oropharyngeal cancers in Canada.

Race, immigrant status, and cancer among women in the United States.

Research on the incidence of cancer among the immigrant population has tended to be of quite a limited scope. We investigate whether immigrant women in the US are less likely to have been recently diagnosed with cancer, and what factors might help to explain any differences identified. We estimate multivariate Logistic regression models to identify the determinants of a diagnosis within the last 3 years of any cancer, of breast cancer and of cervical cancer as well as the use of cancer screening by US women, using self-reported information on cancer diagnosis from consecutive waves of the US National Health Interview Survey over the years 1998-2007. Immigrant women of different ethnic groups are less likely to have been diagnosed with cancer, breast cancer and cervical cancer compared to US-born women. The use of basic health services, including cancer screening, is also lower for immigrant women for each main ethnic group. More research is required to determine whether immigrants may face delays in timely diagnosis of cancer by health care professionals.