An international comparison of cancer survival: metropolitan Toronto, Ontario, and Honolulu, Hawaii

Current State of Geospatial Methodologic Approaches in Canadian Population Oncology Research

Geospatial analyses are increasingly used in population oncology. We provide a first review of geospatial analysis in Canadian population oncology research, compare to international peers, and identify future directions. Geospatial-focused peer-reviewed publications from 1992-2020 were compiled using PubMed, MEDLINE, Web of Science, and Google Scholar. Abstracts were screened for data derived from a Canadian cancer registry and use of geographic information systems. Studies were classified by geospatial methodology, geospatial unit, location, cancer site, and study year. Common limitations were documented from article discussion sections. Our search identified 71 publications using data from all provincial and national cancer registries. Thirty-nine percent (N = 28) were published in the most recent 5-year period (2016-2020). Geospatial methodologies included exposure assessment (32.4%), identifying spatial associations (21.1%), proximity analysis (16.9%), cluster detection (15.5%), and descriptive mapping (14.1%). Common limitations included confounding, ecologic fallacy, not accounting for residential mobility, and small case/population sizes. Geospatial analyses are increasingly used in Canadian population oncology; however, efforts are concentrated among a few provinces and common cancer sites, and data are over a decade old. Limitations were similar to those documented internationally, and more work is needed to address them. Organized efforts are needed to identify common challenges, develop leading practices, and identify shared priorities.

Relation between socioeconomic variables and surgical, systemic and radiation treatment in a cohort of patients with breast cancer in an urban Canadian centre

Background

Studies have shown an association between socioeconomic status and breast cancer treatment. We examined the relation between socioeconomic status and the treatment of breast cancer (surgical, systemic and radiation) in a universal health care system.

Methods

Data from a single urban Canadian centre were collected for consecutive patients who received a diagnosis of breast cancer from January 2010 to December 2011. Variables included patient and disease factors, surgery type, systemic and radiation treatment, and breast reconstruction. Socioeconomic variables were obtained from 2006 Canadian census data. We used multivariable logistic regression to identify predictors of breast cancer treatment.

Results

A total of 721 patients were treated for breast cancer during the study period. Socioeconomic variables were not related to type of breast surgery for breast cancer. Age less than 50 years, having a first-degree relative with breast cancer and income status were predictors of breast reconstruction. Employment status was a consistent predictor of systemic and radiation treatment.

Conclusion

Employment consistently predicted systemic and radiation treatment, and age and income were predictors of breast reconstruction in a universal health care system. Further research is required to determine precisely how socioeconomic factors affect care and to minimize possible disparities in delivery of health care services.

Breast Cancer Care in California and Ontario: Primary Care Protections Greatest Among the Most Socioeconomically Vulnerable Women Living in the Most Underserved Places

BACKGROUND

Better health care among Canada's socioeconomically vulnerable versus America's has not been fully explained. We examined the effects of poverty, health insurance and the supply of primary care physicians on breast cancer care.

METHODS

We analyzed breast cancer data in Ontario (n = 950) and California (n = 6300) between 1996 and 2000 and followed until 2014. We obtained socioeconomic data from censuses, oversampling the poor. We obtained data on the supply of physicians, primary care and specialists. The optimal care criterion was being diagnosed early with node negative disease and received breast conserving surgery followed by adjuvant radiation therapy.

RESULTS

Women in Ontario received more optimal care in communities well supplied by primary care physicians. They were particularly advantaged in the most disadvantaged places: high poverty neighborhoods (rate ratio = 1.65) and communities lacking specialist physicians (rate ratio = 1.33). Canadian advantages were explained by better health insurance coverage and greater primary care access.

CONCLUSIONS

Policy makers ought to ensure that the newly insured are adequately insured. The Medicaid program should be expanded, as intended, across all 50 states. Strengthening America's system of primary care will probably be the best way to ensure that the Affordable Care Act's full benefits are realized.

Colon cancer care and survival: income and insurance are more predictive in the USA, community primary care physician supply more so in Canada

BACKGROUND

Our research group advanced a health insurance theory to explain Canada's cancer care advantages over America. The late Barbara Starfield theorized that Canada's greater primary care-orientation also plays a critically protective role. We tested the resultant Starfield-Gorey theory by examining the effects of poverty, health insurance and physician supplies, primary care and specialists, on colon cancer care in Ontario and California.

METHODS

We analyzed registry data for people with non-metastasized colon cancer from Ontario (n = 2,060) and California (n = 4,574) diagnosed between 1996 and 2000 and followed to 2010. We obtained census tract-based socioeconomic data from population censuses and data on county-level physician supplies from national repositories: primary care physicians, gastroenterologists and other specialists. High poverty neighborhoods were oversampled and the criterion was 10 year survival. Hypotheses were explored with standardized rate ratios (RR) and tested with logistic regression models.

RESULTS

Significant inverse associations of poverty (RR = 0.79) and inadequate health insurance (RR = 0.80) with survival were observed in the California, while they were non-significant or non-existent in Ontario. The direct associations of primary care physician (RRs of 1.32 versus 1.11) and gastroenterologist (RRs of 1.56 versus 1.15) supplies with survival were both stronger in Ontario than California. The supply of primary care physicians took precedence. Probably mediated through the initial course of treatment, it largely explained the Canadian advantage.

CONCLUSIONS

Poverty and health insurance were more predictive in the USA, community physician supplies more so in Canada. Canada's primary care protections were greatest among the most socioeconomically vulnerable. The protective effects of Canadian health care prior to enactment of the Affordable Care Act (ACA) clearly suggested the following. Notwithstanding the importance of insuring all, strengthening America's system of primary care will probably be the best way to ensure that the ACA's full benefits are realized. Finally, Canada's strong primary care system ought to be maintained.

Survey of American and Canadian general surgeons' perceptions of margin status and practice patterns for breast conserving surgery

Although breast conservation surgery (BCS) is commonly performed, several aspects of the procedure remain controversial. We undertook a cross-sectional survey to compare Canadian (CDN) and American (AM) general surgeons' reported BCS practice patterns to better understand the cross-border differences in early-stage breast cancer surgery care. A modified Dillman Method survey was mailed to 1,447 AM and 1,443 CDN surgeons. Factors evaluated included preoperative assessment, margin definition, surgical techniques, and re-excision practices. The response rate was 26% and 51% for AM and CDN surgeons, respectively. There was variation in use of preoperative core biopsies. American surgeons required wider margins for invasive cancer and ductal carcinoma in situ, and more often recommend re-excision for invasive cancer with 1 and 2 mm margins (p < 0.05). There was also variability in surgical techniques used for intraoperative margin assessment. Wide variation in BCS practice was observed, with some of this variability related to surgeon country.

Mediation of the effects of living in extremely poor neighborhoods by health insurance: breast cancer care and survival in California, 1996 to 2011

BACKGROUND

We examined the mediating effect of health insurance on poverty-breast cancer care and survival relationships and the moderating effect of poverty on health insurance-breast cancer care and survival relationships in California.

METHODS

Registry data for 6,300 women with breast cancer diagnosed between 1996 and 2000 and followed until 2011 on stage at diagnosis, surgeries, adjuvant treatments and survival were analyzed. Socioeconomic data were obtained for residences from the 2000 census to categorize neighborhoods: high poverty (30% or more poor), middle poverty (5%-29% poor) and low poverty (less than 5% poor). Primary payers or health insurers were Medicaid, Medicare, private or uninsured.

RESULTS

Evidence of survival mediation was observed for women with node negative breast cancer. The apparent effect of poverty disappeared in the presence of Medicare or private health insurance. Women who were so insured were advantaged on 8-year survival compared to the uninsured or those insured by Medicaid (OR = 1.89). Evidence of payer moderation by poverty was also observed for women with node negative breast cancer. The survival advantaging effect of Medicare or private insurance was stronger in low poverty (OR = 1.81) than it was in middle poverty (OR = 1.57) or in high poverty neighborhoods (OR = 1.16). This same pattern of mediated and moderated effects was also observed for early stage at diagnosis, shorter waits for adjuvant radiation therapy and for the receipt of sentinel lymph node biopsies. These findings are consistent with the theory that more facilitative social and economic capital is available in low poverty neighborhoods, where women with breast cancer may be better able to absorb the indirect and direct, but uncovered, costs of care. As for treatments, main protective effects as well as moderator effects indicative of protection, particularly in high poverty neighborhoods were observed for women with private health insurance.

CONCLUSIONS

America's multi-tiered health insurance system mediates the quality of breast cancer care. The system is inequitable and unjust as it advantages the well insured and the well to do. Recent health care reforms ought to be enacted in ways that are consistent with their federal legislative intent, that high quality health care be truly available to all.

Effects of being uninsured or underinsured and living in extremely poor neighborhoods on colon cancer care and survival in California: historical cohort analysis, 1996-2011

Background

We examined the mediating effects of health insurance on poverty-colon cancer care and survival relationships and the moderating effects of poverty on health insurance-colon cancer care and survival relationships among women and men in California.

Methods

We analyzed registry data for 3,291 women and 3,009 men diagnosed with colon cancer between 1996 and 2000 and followed until 2011 on lymph node investigation, stage at diagnosis, surgery, chemotherapy, wait times and survival. We obtained socioeconomic data for individual residences from the 2000 census to categorize the following neighborhoods: high poverty (30% or more poor), middle poverty (5-29% poor) and low poverty (less than 5% poor). Primary health insurers were Medicaid, Medicare, private or none.

Results

Evidence of mediation was observed for women, but not for men. For women, the apparent effect of poverty disappeared in the presence of payer, and the effects of all forms of health insurance seemed strengthened. All were advantaged on 6-year survival compared to the uninsured: Medicaid (RR = 1.83), Medicare (RR = 1.92) and private (RR = 1.83). Evidence of moderation was also only observed for women. The effects of all forms of health insurance were stronger for women in low poverty neighborhoods: Medicaid (RR = 2.90), Medicare (RR = 2.91) and private (RR = 2.60). For men, only main effects of poverty and payers were observed, the advantaging effect of private insurance being largest. Across colon cancer care processes, Medicare seemed most instrumental for women, private payers for men.

Conclusions

Health insurance substantially mediates the quality of colon cancer care and poverty seems to make the effects of being uninsured or underinsured even worse, especially among women in the United States. These findings are consistent with the theory that more facilitative social and economic capital is available in more affluent neighborhoods, where women with colon cancer may be better able to absorb the indirect and direct, but uncovered, costs of care.

Assessing barriers to health insurance and threats to equity in comparative perspective: the Health Insurance Access Database

BACKGROUND

Typologies traditionally used for international comparisons of health systems often conflate many system characteristics. To capture policy changes over time and by service in health systems regulation of public and private insurance, we propose a database containing explicit, standardized indicators of policy instruments.

METHODS

The Health Insurance Access Database (HIAD) will collect policy information for ten OECD countries, over a range of eight health services, from 1990-2010. Policy indicators were selected through a comprehensive literature review which identified policy instruments most likely to constitute barriers to health insurance, thus potentially posing a threat to equity. As data collection is still underway, we present here the theoretical bases and methodology adopted, with a focus on the rationale underpinning the study instruments.

RESULTS

These harmonized data will allow the capture of policy changes in health systems regulation of public and private insurance over time and by service. The standardization process will permit international comparisons of systems' performance with regards to health insurance access and equity.

CONCLUSION

This research will inform and feed the current debate on the future of health care in developed countries and on the role of the private sector in these changes.

Neighborhood deprivation and clinical outcomes among head and neck cancer patients

The unique effects of neighborhood-level economic deprivation on survival, recurrence, and second primary malignancy development were examined using adjusted Cox proportional hazards regression models among 1151 incident squamous cell carcinomas of the head and neck patients. Cancer site was examined as a potential moderator. Main analyses yielded null results; however, interaction analyses indicated poorer overall survival [HR=1.59 (1.00-2.53)] and greater second primary malignancy development [HR=2.99 (1.46-6.11)] among oropharyngeal cancer patients from highly deprived neighborhoods relative to less deprived neighborhoods. Results suggest a dual focus on individual and neighborhood risk factors could help improve clinical outcomes among oropharyngeal cancer patients.

A geographical analysis of breast cancer clustering in southern Ontario: generating hypotheses on environmental influences

This article presents the results of spatial analysis of breast cancer clustering in southern Ontario. Data from the Cancer Care Ontario were analyzed using the Scan Statistic at the level of county, with further analysis conducted within counties that were identified as primary clusters at the dissemination area level. The results identified five counties as primary clusters of women diagnosed with breast cancer between 1986 and 2002: Essex (relative risk [RR] =1.096-1.061; p<0.001), Lambton (RR=1.05-1.167), Chatham-Kent (RR=1.133-1.191), Niagara (RR=1.228-1.290) and Toronto (RR=1.152-1.146). The within county analysis revealed several DAs with significantly higher (RR>3, p<0.05) rates of breast cancer, and supports our hypothesis that breast cancer risk in southern Ontario may be associated with industrial and environmental (such as pesticides) pollutants. Further research is needed to verify the environmental links within the identified clusters.

Socioeconomic status and chemotherapy use for melanoma in older people

The study objective was to examine the association, among older persons with cutaneous melanoma, between areal socioeconomic status (SES) and receiving chemotherapy. SEER-Medicare-linked database (1,239 white men and women aged ≥ 66, with invasive melanoma [regional and distant stages]; 1991-1999) was used. SES was measured by census tract poverty level (average of 1990 and 2000 Census data). Covariates were sociodemographics, tumor characteristics, and comorbidity index. Residing in poorer SES areas was associated with a lower likelihood for receiving chemotherapy among patients in the overall sample (adjusted odds ratios = OR 0.97, 95% confidence interval = CI 0.95-0.99), and those with regional stage at diagnosis (OR 0.97, 95% CI 0.94-0.98). These findings reflect socioeconomic disparities in chemotherapy use for melanoma among older white patients in the United States.

[Association between socioeconomic status and all-cause mortality after breast cancer surgery: nationwide retrospective cohort study]

OBJECTIVES

This study aims to evaluate and explain the socioeconomic inequalities of all-cause mortality after breast cancer surgery in South Korea.

METHODS

This population based study included all 8868 females who underwent radical mastectomy for breast cancer between January 2002 and June 2003. Follow-up for mortality continued from January 2002 to June 2006. The patients were divided into 4 socioeconomic classes according to their socioeconomic status as defined by the National Health Insurance contribution rate. The relationship between socioeconomic status and all-cause mortality after breast cancer surgery was assessed using the Cox proportional hazards model with adjusting for age, the Charlson's index score, emergency hospitalization, the type of hospital and the hospital ownership.

RESULTS

Those in the lowest socioeconomic status group had a significantly higher hazard ratio of 2.09 (95% CI =1.50 - 2.91) compared with those in the highest socioeconomic group after controlling for all the identifiable confounding variables. For all-cause mortality after radical mastectomy, all the other income groups showed significantly higher 3-year mortality rates than did the highest income group.

CONCLUSIONS

The socioeconomic status of breast cancer patients should be considered as an independent prognostic factor that affects all-cause mortality after radical mastectomy, and this is possibly due to a delayed diagnosis, limited access or minimal treatment leading to higher mortality. This study may provide tangible support to intensify surveillance and treatment for breast cancer among low socioeconomic class women.

Income and long-term breast cancer survival: comparisons of vulnerable urban places in Ontario and California

Effects of socioeconomic status on the long-term survival of 808 women with node-negative breast cancer in Canada and the United States were observed. Ontario and California samples diagnosed between 1988 and 1990 were followed until 2006. Socioeconomic data were taken from population censuses. Compared with their California counterparts, residents of low-income urban areas in Ontario experienced a significant 15-year survival advantage (RR = 1.66 [95% CI: 1.00, 2.76]). In these and other vulnerable, lower-middle- to working-class neighborhoods, significantly more Ontario residents gained access to adjuvant radiation therapy (RR = 1.75 [1.21, 2.53]) which seemed associated with better long-term survival (RR = 1.36 [0.99, 1.86]). This stage-adjusted, historical cohort analysis suggests much greater cancer care equity in Canada than in the United States.

Impact of socioeconomic status on prostate cancer diagnosis, treatment, and prognosis

BACKGROUND

The objective of the current study was to evaluate the impact of socioeconomic disparities on prostate cancer presentation, treatment, and prognosis in Geneva, Switzerland, in which healthcare costs, medical coverage, and life expectancy are considered to be among the highest in the world.

METHODS

This population-based study included all patients diagnosed with invasive prostate cancer among the resident population between 1995 and 2005. Patients were divided into 3 socioeconomic groups according to their last known occupation. Compared were patient and tumor characteristics and treatment patterns between socioeconomic groups. Cox multivariate regression analysis was used to assess and explain socioeconomic inequalities in prostate cancer-specific mortality.

RESULTS

Compared with patients of high socioeconomic class, those of low socioeconomic class were more often foreigners, were found less frequently to have screen-detected cancer, were found to have a more advanced stage of disease at diagnosis, and less often had information regarding disease characteristics and staging. These patients underwent prostatectomy less frequently and were more often managed with watchful waiting. The risk of dying as a result of prostate cancer (hazards ratio [HR]) in patients of a low versus high socioeconomic status was increased 2-fold (95% confidence interval [95% CI], 1.5-2.6). After adjustment for patient and tumor characteristics and treatment, the mortality risk was no longer found to be significantly increased (HR, 1.2; 95% CI, 0.8-1.6).

CONCLUSIONS

In the current study, patients of low socioeconomic class were found to be at increased risk of dying as a result of their prostate cancer. This increased mortality is largely attributable to delayed diagnosis, poor diagnostic workup, and less invasive treatments in these individuals.

Physician supply and breast cancer survival

BACKGROUND

This study tested the hypothesis that physician supply thresholds are associated with breast cancer survival in Ontario.

METHODS

The 5-year survival of 17,820 female breast cancer patients diagnosed between 1995 and 1997 was surveilled until 2003 for all-cause mortality. Physician supply densities in 1991 and 2001 were computed for 49 Ontario regions.

RESULTS

There were independent threshold effects for general practitioners (GP; 7.25 per 10,000) and obstetrician/gynecologists (OB/GYN; 6 per 100,000) at or above which women with breast cancer were more likely to survive for 5 years. The respective risk of living in areas undersupplied with OB/GYN and GP increased 30% to nearly 5-fold during the 1990s. Five-year survival tended to be lower in provincial areas outside of Toronto, which experienced GP (odds ratio, 0.83; 90% CI, 0.70-0.99) and OB/GYN (odds ratio, 0.76; 95% CI, 0.61-0.96) supply decreases.

CONCLUSION

As they do in America, primary care physician supplies in Canada seem to matter in the effective provision of cancer care. Community resources such as health care service endowments, including physician supplies, may be particularly critical to the performance of health care systems such as Canada's, which aim to provide medically necessary care for all.

Breast cancer care in the Canada and the United States: ecological comparisons of extremely impoverished and affluent urban neighborhoods

This study examined the differential effect of extreme impoverishment on breast cancer care in urban Canada and the United States. Ontario and California registry-based samples diagnosed between 1998 and 2000 were followed until 2006. Extremely poor and affluent neighborhoods were compared. Poverty was associated with non-localized disease, surgical and radiation therapy (RT) waits, non-receipt of breast conserving surgery, RT and hormonal therapy, and shorter survival in California, but not in Ontario. Extremely poor Ontario women were consistently advantaged on care indices over their California counterparts. More inclusive health insurance coverage in Canada seems the most plausible explanation for such Canadian breast cancer care advantages.

Associations of physician supplies with breast cancer stage at diagnosis and survival in Ontario, 1988 to 2006

BACKGROUND

The authors examined whether the supply of primary care physicians had protective effects on breast cancer stage and survival in Ontario and whether supply losses during the 1990s were associated with diminished protection.

METHODS

Random samples of the Ontario Cancer Registry, respectively, provided 879 women and 951 women who were diagnosed with breast cancer between 1988 and 1990 (followed until 1996) and 1998 and 2000 (followed until 2006), respectively. Active physician supply data (1991 and 2001) joined to each woman's census division of residence was taken from the Scott's Medical Database.

RESULTS

Protective thresholds were observed among the earlier cohort for supplies of general practitioners (7 per 10,000 population) and supplies of obstetricians/gynecologists (6 per 100,000 population) at or above which women with breast cancer were significantly more likely to have been diagnosed with localized disease and to have survived for >or=5 years. These protective effects seemed generally attenuated among the more recent cohort. The risk of living in primary care physician-undersupplied areas increased significantly between 1991 and 2001 (10%-30%), and such physician supply losses were associated with reduced cancer care protection, including less prevalent early diagnoses (odds ratio [OR], 1.60; 95% confidence interval [95% CI], 1.00-2.58) and lower 5-year survival rates (OR, 1.62; 95% CI, 1.03-2.55).

CONCLUSIONS

Primary care physician supplies appeared to matter very much in the effective provision of cancer care in Canada. Community healthcare service endowments that include adequate physician supplies may be particularly critical to the performance of a healthcare system such as that in Canada, which provides universal accessibility to medically necessary care.

Access to emergency operative care: a comparative study between the Canadian and American health care systems

BACKGROUND

Canada provides universal health insurance to all citizens, whereas 47 million Americans are uninsured. There has not been a study comparing access to emergency operative care between the 2 countries. As both countries contemplate changes in health care delivery, such comparisons are needed to guide health policy decisions. The purpose of this study is to determine whether or not there is a difference in access to emergency operative care between Canada and the United States.

METHODS

All patients diagnosed with acute appendicitis from 2001 to 2005 were identified in the Canadian Institute for Health Information database and the US Nationwide Inpatient Sample. Severity of appendicitis was determined by ICD-9 codes. Patients were further characterized by age, gender, insurance status, race, and socioeconomic status (SES; income). Univariate and multivariate analyses were performed to determine the odds of appendiceal perforation at different levels of SES in each country.

RESULTS

There were 102,692 Canadian patients and 276,890 American patients with acute appendicitis. In Canada, there was no difference in the odds of perforation between income levels. In the United States, there was a significant, inverse relationship between income level and the odds of perforation. The odds of perforation in the lowest income quartile were significantly higher than the odds of perforation in the highest income bracket (odds ratio, 1.20; 95% confidence interval, 1.16-1.24).

CONCLUSION

The results suggest that access to emergency operative care is related to SES in the United States, but not in Canada. This difference could result from the concern over the ability to pay medical bills or the lack of a stable relationship with a primary care provider that can occur outside of a universal health care system.

Wait times for surgical and adjuvant radiation treatment of breast cancer in Canada and the United States: greater socioeconomic inequity in America

PURPOSE

The demand for cancer care has increased among aging North American populations as cancer treatment innovations have proliferated. Gaps between supply and demand may be growing. This study examined whether socioeconomic status has a differential effect on waits for surgical and adjuvant radiation treatment (RT) of breast cancer in Canada and the US.

METHODS

Ontario and California cancer registries provided 929 and 984 breast cancer cases diagnosed between 1998 and 2000 in diverse urban and rural places. Residence-based socioeconomic data were taken from censuses. Cancer care variables were reliably abstracted from health records: stage, receipt of surgery and RT, and waits from diagnosis to initial and initial to adjuvant treatment. Median waits were compared within- and between-country with the non-parametric Mann-Whitney U-test. Categorically long, age-adjusted wait comparisons used the Mantel-Haenszel chi-square test.

RESULTS

There were significant associations between lower socioeconomic status and longer surgical waits, lower access to adjuvant RT and to longer RT waits across diverse places in California. None were observed in Ontario. The two cohorts did not practically differ on access to surgery or on surgical waits. Compared with their counterparts in California, low-income Ontarians, particularly those in small urban places, gained greater access to RT, while high-income Americans had shorter waits for RT.

CONCLUSIONS

This historical study contextualized Canada's "waiting-list problems" with evidence on breast cancer care, where lower income Americans seemed to have waited as long as similar Canadians. Many more low-income Americans seemed to experience the longest wait of all for adjuvant care. They simply did not receive it. In contrast to stark American socioeconomic inequity, this study evidenced remarkable equity in Canadian breast cancer care.

Breast cancer survival in ontario and california, 1998-2006: socioeconomic inequity remains much greater in the United States

This study re-examined the differential effect of socioeconomic status on the survival of women with breast cancer in Canada and the United States. Ontario and California cancer registries provided 1,913 cases from urban and rural places. Stage-adjusted cohorts (1998-2000) were followed until 2006. Socioeconomic data were taken from population censuses. SES-survival associations were observed in California, but not in Ontario, and Canadian survival advantages in low-income areas were replicated. A better controlled and updated comparison reaffirmed the equity advantage of Canadian health care.

Breast cancer survival in Canada and the USA: meta-analytic evidence of a Canadian advantage in low-income areas

BACKGROUND

This study tested the hypothesis that relatively poor Canadian women with breast cancer have a survival advantage over their counterparts in the USA.

METHODS

Seventy-eight independent retrospective cohort (incidence between 1984 and 2000, followed until 2006) outcomes were synthesized. Fixed effects meta-regression models compared women with breast cancer in low-income areas of Canada and the USA.

RESULTS

Low-income Canadian women were advantaged on survival [rate ratio (RR) = 1.14; 95% confidence interval (CI) 1.13-1.15] and their advantage was even larger among women <65 years of age who are not yet eligible for Medicare coverage in the USA (RR = 1.21, 95% CI 1.18-1.24). Canadian advantages were also larger for node positive breast cancer, which may present with greater clinical and managerial discretion (RR = 1.40, 95% CI 1.30-1.50), and smaller when Hawaii, the state providing the most Canadian-like access, was the US comparator (RR = 1.12, 95% CI 1.01-1.20).

CONCLUSIONS

More inclusive health care insurance coverage in Canada vs the USA, particularly among each country's relatively poor people, seems the most plausible explanation for such Canadian advantages. Provision of health care for all Americans would likely prevent countless early deaths, particularly among the relatively poor.

Insurance status and the severity of breast cancer at the time of diagnosis

RATIONALE AND OBJECTIVES

To evaluate how the insurance status of women diagnosed with breast cancer correlates with size and stage at the time of diagnosis.

METHODS AND MATERIALS

The age-adjusted incidence of early- and late-stage breast cancer as determined by the tumor node metastasis classification system of stages in situ, local, regional, or distant was calculated for insured and uninsured women from our institution's database between 2002 and 2004. Late-stage breast cancer was defined as present when patients had either regional or distant disease. Statistical analysis was conducted using generalized linear models and chi(2) tests.

RESULTS

There were a total of 617 patients in our retrospective study. Of these, 564 (91.4%) had insurance and 53 (8.6%) were uninsured. Four hundred forty-seven (72.4%) patients were Caucasian and 170 (27.6%) patients were non-Caucasian. Of the 463 patients with early-stage breast cancer (0, I, or II), 433 (93.5%) had insurance and 30 (6.5%) were uninsured. Of the 154 patients with late-stage breast cancer (III or IV), 131 (85.1%) had insurance and 23 (14.9%) patients were uninsured. Analysis demonstrated that there was a significant effect in the insurance status on cancer stage (P = .006) and tumor size (P = .010). Compared to insured patients, uninsured patients had a 66% higher likelihood of presenting with a late-stage cancer and larger tumor. The analysis from the chi(2) test also supports the above with a significant association between patients' cancer stage and insurance status (P = .001) and also between tumor size and insurance status (P = .001). Patients' ages and geographic locations were not significant correlated with size and stage, but non-Caucasians had a significantly higher risk of larger tumors and more advanced stage than Caucasians (P < .005).

CONCLUSIONS

Uninsured, non-Caucasian patients have a higher probability of presenting with a more advanced stage of breast cancer and larger tumor size than patients with insurance in a large university multidisciplinary breast cancer population.

Cancer survival in Ontario, 1986-2003: evidence of equitable advances across most diverse urban and rural places

OBJECTIVES

This study examined whether place and socio-economic status had differential effects on the survival of women diagnosed with breast cancer in Ontario during the 1980s and the 1990s.

METHODS

The Ontario Cancer Registry provided 29,934 primary malignant breast cancer cases. Successive historical cohorts (1986-1988 and 1995-1997) were, respectively, followed until 1994 and 2003. Diverse places were compared: the greater metropolitan Toronto area, other cities, ranging in size from 50,000 to a million people, smaller towns and villages, and rural and remote areas. Socio-economic data for each woman's residence at the time of diagnosis were taken from population censuses.

RESULTS

Very small cities (6%) with populations between 50,000 and 100,000 were the only places where breast cancer survival had advanced less compared to the province as a whole. Income gradients began to appear, however, in larger cities. Urban residents in the lowest income areas were significantly disadvantaged compared to the highest income areas during the 1990s, but not during the 1980s.

CONCLUSION

This historical analysis of breast cancer survival evidenced remarkably equitable advances across nearly all of Ontario's diverse places. The most likely explanation for such substantial equity seems to be Canada's universally accessible, single-payer, health care system.

Increased racial differences on breast cancer care and survival in America: historical evidence consistent with a health insurance hypothesis, 1975-2001

PURPOSE

This study examined whether race/ethnicity had differential effects on breast cancer care and survival across age strata and cohorts within stages of disease.

METHODS

The Detroit Cancer Registry provided 25,997 breast cancer cases. African American and non-Hispanic white, older Medicare-eligible and younger non-eligible women were compared. Successive historical cohorts (1975-1980 and 1990-1995) were, respectively, followed until 1986 and 2001.

RESULTS

African American disadvantages on survival and treatments increased significantly, particularly among younger women who were much more likely to be uninsured. Within node positive disease all treatment disadvantages among younger African American women disappeared with socioeconomic adjustment.

CONCLUSIONS

Growth of this racial divide implicates social, rather than biological, forces. Its elimination will require high quality health care for all.

Socioeconomic status and health-related quality of life among elderly people: results from the Joint Canada/United States Survey of Health

The objective of this study was to assess the independent effect of income on health-related quality of life (HRQL) among older adults in Canada and the United States. Data were obtained from the 2002-2003 Joint Canada/United States Survey of Health. The sample consisted of 755 Canadians and 1,151 Americans aged 65 years or older. HRQL was measured with the multidimensional Health Utilities Index Mark 3 (HUI3). The results indicated that in the elderly population, HRQL was significantly associated with household income in the United States but not in Canada, controlling for sociodemographic and health indicators. Various explanations for the positive linear relationship between HRQL and income in the elderly population are discussed, including the roles of access to health care and socioeconomic inequalities in the United States and Canada.

A systematic review of studies comparing health outcomes in Canada and the United States

BACKGROUND

Differences in medical care in the United States compared with Canada, including greater reliance on private funding and for-profit delivery, as well as markedly higher expenditures, may result in different health outcomes.

OBJECTIVES

To systematically review studies comparing health outcomes in the United States and Canada among patients treated for similar underlying medical conditions.

METHODS

We identified studies comparing health outcomes of patients in Canada and the United States by searching multiple bibliographic databases and resources. We masked study results before determining study eligibility. We abstracted study characteristics, including methodological quality and generalizability.

RESULTS

We identified 38 studies comparing populations of patients in Canada and the United States. Studies addressed diverse problems, including cancer, coronary artery disease, chronic medical illnesses and surgical procedures. Of 10 studies that included extensive statistical adjustment and enrolled broad populations, 5 favoured Canada, 2 favoured the United States, and 3 showed equivalent or mixed results. Of 28 studies that failed one of these criteria, 9 favoured Canada, 3 favoured the United States, and 16 showed equivalent or mixed results. Overall, results for mortality favoured Canada (relative risk 0.95, 95% confidence interval 0.92-0.98, p= 0.002) but were very heterogeneous, and we failed to find convincing explanations for this heterogeneity. The only condition in which results consistently favoured one country was end-stage renal disease, in which Canadian patients fared better.

INTERPRETATION

Available studies suggest that health outcomes may be superior in patients cared for in Canada versus the United States, but differences are not consistent.

Origins of socio-economic inequalities in cancer survival: a review

BACKGROUND

Cancer survival is known to vary by socio-economic group. A review of studies published by 1995 showed this association to be universal and resilient to the many different ways in which socio-economic status was determined. Differences were most commonly attributed to differences in stage of disease at diagnosis.

MATERIALS AND METHODS

A review of research published since 1995 examining the association of cancer survival with socio-economic variables.

RESULTS

An association between socio-economic status and cancer survival has continued to be demonstrated in the last decade of research. Stage at diagnosis and differences in treatment have been cited as the most important explanatory factors. Some research has evaluated the psychosocial elements of this association.

CONCLUSIONS

Socio-economic differences in cancer survival are now well documented. The explanatory power of stage at diagnosis, although great, should not detract from the evidence of differential treatment between social groups. Neither factor can completely explain the observed socio-economic differences in survival, however, and the importance of differences in tumour and patient factors should now be quantified.

Social disparities and prostate cancer: mapping the gaps in our knowledge

To evaluate the current state of our knowledge regarding social disparities and prostate cancer and to map the domains where substantial knowledge has been acquired as well as those where little is known, with the purpose of identifying important areas for future research. A Medline research was conducted to identify published papers regarding social disparities in prostate cancer since 1990. The results of this review are presented in a social disparities and prostate cancer grid designed to highlight which domains of social disparities have been researched and which neglected. The major social disparity in prostate cancer concerns the extremely high prostate cancer incidence and mortality seen among black Americans. This is also the area where the most research has been performed. Low socioeconomic position is associated with poorer prostate cancer outcomes but not with higher prostate cancer incidence. It remains poorly defined to what extent racial/ethnic differences in prostate cancer result from differences in socioeconomic position (SEP). Understanding the causes of the high prostate cancer mortality seen among black men remains the major challenge in the area of social disparities and prostate cancer.

Mortality of white Americans, African Americans, and Canadians: the causes and consequences for health of welfare state institutions and policies

The life expectancy of African Americans has been substantially lower than that of white Americans for as long as records are available. The life expectancy of all Americans has been lower than that of all Canadians since the beginning of the 20th century. Until the 1970s this disparity was the result of the low life expectancy of African Americans. Since then, the life expectancy of white Americans has not improved as much as that of all Canadians. This article discusses two issues: racial disparities in the United States, and the difference in life expectancy between all Canadians and white Americans. Each country's political culture and institutions have shaped these differences, especially national health insurance in Canada and its absence in the United States. The American welfare state has contributed to and explains these differences.

Socioeconomic determinants of mortality in two Canadian provinces: Multilevel modelling and neighborhood context

The influence of individual and contextual socioeconomic variables on mortality is compared in two Canadian provinces, Manitoba and Nova Scotia. Although differing substantially in size, ethnic mix, and history, both provinces provide greater access to health and social services as well as fewer income inequalities than the United States. A total of 8032 Manitoba respondents (followed from 1996-97 to 2002) and 2116 Nova Scotia respondents (followed from 1990 to 1999) were linked to the appropriate Canadian census as a source of neighborhood characteristics. Data were analyzed using individual- and multi-level logistic regression. Well-educated and higher income individuals were less likely to die during follow-up. No significant direct effect was found between neighborhood socioeconomic characteristics and mortality. However, both provinces showed an increased importance of individual income vis-à-vis mortality in advantaged neighborhoods relative to disadvantaged neighborhoods. Additional Manitoba analyses showed a "healthy mover" effect among respondents changing place of residence, regardless of whether they moved to more advantaged or more disadvantaged neighborhoods. The findings are discussed in the context of differences in health and health care among Canada, the United States, and other OECD countries.

Residence, income and cancer hospitalizations in British Columbia during a decade of policy change

Background

Through the 1990s, governments across Canada shifted health care funding allocation and organizational foci toward a community-based population health model. Major concerns of reform based on this model include ensuring equitable access to health and health care, and enhancing preventive and community-based resources for care. Reforms may act differentially relative to specific conditions and services, including those geared to chronic versus acute conditions. The present study therefore focuses on health service utilization, specifically cancer hospitalizations, in British Columbia during a decade of health system reform.

Methods

Data were drawn from the British Columbia Linked Health Data resource; income measures were derived from Statistics Canada 1996 Census public use enumeration area income files. Records with a discharge (separation) date between 1 January 1991 and 31 December 1998 were selected. All hospitalizations with ICD-9 codes 140 through 208 (except skin cancer, code 173) as principal diagnosis were included. Specific cancers analyzed include lung; colorectal; female breast; and prostate. Hospitalizations were examined in total (all separations), and as divided into first and all other hospitalizations attributed to any given individual. Annual trends in age-sex adjusted rates were analyzed by joinpoint regression; longitudinal multivariate analyses assessing association of residence and income with hospitalizations utilized generalised estimating equations. Results are evaluated in relation to cancer incidence trends, health policy reform and access to care.

Results

Age-sex adjusted hospitalization rates for all separations for all cancers, and lung, breast and prostate cancers, decreased significantly over the study period; colorectal cancer separations did not change significantly. Rates for first and other hospitalizations remained stationary or gradually declined over the study period. Area of residence and income were not significantly associated with first hospitalizations; effects were less consistent for all and other hospitalizations. No interactions were observed for any category of separations.

Conclusions

No discontinuities were observed with respect to total hospitalizations that could be associated temporally with health policy reform; observed changes were primarily gradual. These results do not indicate whether equity was present prior to health care reform. However, findings concur with previous reports indicating no change in access to health care across income or residence consequent on health care reform.

Socioeconomic disparities in health care use: Does universal coverage reduce inequalities in health?

BACKGROUND

Despite enormous public sector expenditures, the effectiveness of universal coverage for health care in reducing socioeconomic disparities in health has received little attention.

STUDY OBJECTIVE

s: To evaluate whether universal coverage for health care reduces socioeconomic disparities in health.

DESIGN

Information on participants of the 1990 Nova Scotia Nutrition Survey was linked with eight years of administrative health services data and mortality. The authors first examined whether lower socioeconomic groups use more health services, as would be expected given their poorer health status. They then investigated to what extent differential use of health services modifies socioeconomic disparities in mortality. Finally, the authors evaluated health services use in the last years of life when health is poor regardless of a person's socioeconomic background.

SETTING

The Canadian province of Nova Scotia, which provides universal health care coverage to all residents.

PARTICIPANTS

1816 non-institutionalised adults, aged 18-75 years, from a two stage cluster sample stratified by age, gender, and region.

MAIN RESULTS

People with lower socioeconomic background used comparatively more family physician and hospital services, in such a way as to ameliorate the socioeconomic differences in mortality. In contrast, specialist services were comparatively underused by people in lower socioeconomic groups. In the last three years of life, use of specialist services was significantly higher in the highest income group.

CONCLUSIONS

Universal coverage of family physician and hospital services ameliorate the socioeconomic differences in mortality. However, specialist services are underused in lower socioeconomic groups, bearing the potential to widen the socioeconomic gap in health.

An international comparison of breast cancer survival: Winnipeg, Manitoba and Des Moines, Iowa, metropolitan areas

PURPOSE

Extending previous Canadian-United States cancer survival comparisons in large metropolitan areas, this study compares breast cancer survival in smaller metropolitan areas: Winnipeg, Manitoba and Des Moines, Iowa.

METHODS

Manitoba and Iowa cancer registries, respectively, provided a total of 2,383 and 1,545 women with breast cancer (1984 to 1992, followed until December 31, 1997). Socioeconomic data for each person's residence at the time of diagnosis was taken from population censuses.

RESULTS

Socioeconomic status and breast cancer survival were directly associated in the US cohort, but not in the Canadian cohort. Compared with similar patients in Des Moines, residents of the lowest fifth of income areas in Winnipeg experienced a significant 5-year survival advantage (survival rate ratio [SRR] = 1.14). In these lowest income areas, the Canadian survival advantage was larger among women aged 25 to 64 years (SRR = 1.23), and this was observed in the middle fifth of income areas among this younger cohort (SRR = 1.11). The Canadian survival advantage even seemed apparent in the poorest neighborhoods with relatively high representations of Aboriginal people (SRR = 1.16).

CONCLUSION

This study replicated the finding of advantaged Canadian cancer survival in smaller metropolitan areas that had been consistently observed in larger metropolitan areas. Canada's single payer health care system seems to offer similar advantages across a number of diverse urban contexts.

Survival of breast cancer patients in Connecticut in relation to socioeconomic and health care access indicators

The purpose of this study of 16,931 black and white Connecticut women diagnosed with invasive breast cancer in 1988-1995 was to examine survival in relation to surrogate or proxy indicators of both socioeconomic status (SES) and access to primary care. Patients were followed through 1998, and the risk of death was elevated for the lowest (vs. highest) SES category independent of stage at diagnosis and other characteristics, especially among patients diagnosed before age 65 years. The health care access indicator was not associated with risk of death when other patient characteristics (including the SES variable and stage at diagnosis) were taken into account. Unexplained elevations, relative to the rest of the state, in risk of death were found for patients diagnosed while living in two of the state's four largest cities.