An international comparison of cancer survival: Toronto, Ontario, and Detroit, Michigan, metropolitan areas

Access to care, health status, and health disparities in the United States and Canada: results of a cross-national population-based survey

OBJECTIVES

We compared health status, access to care, and utilization of medical services in the United States and Canada and compared disparities according to race, income, and immigrant status.

METHODS

We analyzed population-based data on 3505 Canadian and 5183 US adults from the Joint Canada/US Survey of Health. Controlling for gender, age, income, race, and immigrant status, we used logistic regression to analyze country as a predictor of access to care, quality of care, and satisfaction with care and as a predictor of disparities in these measures.

RESULTS

In multivariate analyses, US respondents (compared with Canadians) were less likely to have a regular doctor, more likely to have unmet health needs, and more likely to forgo needed medicines. Disparities on the basis of race, income, and immigrant status were present in both countries but were more extreme in the United States.

CONCLUSIONS

United States residents are less able to access care than are Canadians. Universal coverage appears to reduce most disparities in access to care.

Mortality after kidney transplantation: a comparison between the United States and Canada

There is a paucity of comparative studies on country-specific outcomes in kidney transplantation. We compared post-transplant mortality among primary, adult, solitary kidney transplant recipients (KTR) from the United States (n = 70 708) and Canada (n = 5773), between January 1, 1991 and December 31, 1998, using data from the Scientific Registry of Transplant Recipients and the Canadian Organ Replacement Register. Multivariable Cox regression revealed higher adjusted post-transplant mortality among U.S. (vs. Canadian) KTR (HR = 1.35 [95% CI 1.24, 1.47; p < 0.005]). Mortality risk in the first post-transplant year was similar in both countries but higher in the United States beyond the first year (HR = 1.49-1.53; p < 0.005). There was no difference in mortality among patients transplanted within 1 year of starting dialysis, but mortality was increased in U.S. (vs. Canadian) patients after 1-2 and 4+ years on dialysis (HR = 1.36-1.66; p < 0.005). Greater mortality was also seen in U.S. patients with diabetes mellitus and/or graft failure. In conclusion, there are considerable differences in the survival of KTR in the United States and Canada. A detailed examination of factors contributing to this variation may yield important insights into improving outcomes for all KTR.

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.

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.

Rationale and design of the National Program of Cancer Registries' breast, colon, and prostate cancer patterns of care study

BACKGROUND

Investigators from the Centers for Disease Control and Prevention (CDC), National Program of Cancer Registries (NPCR), are collaborating with public health professionals from seven states and the District of Columbia to conduct the Patterns of Care study to assess the quality of cancer data and to determine whether stage-specific treatments are being carried out.

METHODS

To assess the quality and completeness of cancer care data in the United States, trained staff from the Patterns of Care study are abstracting medical records to obtain detailed clinical data on treatment, tumor characteristics, stage at diagnosis, and demographics of representative samples of patients diagnosed with breast, colon, and prostate cancer. Altogether staff from each of the eight participating cancer registries will abstract 500 cases of breast, prostate, and colon/rectum/anus cancer for the CONCORD study and an additional 150 cases of localized breast cancer, 100 cases of stage III colon cancer, and 100 cases of localized prostate cancer for the Patterns of Care study. Chi-square tests will be used to compare routine registry data with re-abstracted data. The investigators will use logistic regression techniques to describe the characteristics of patients with localized breast and prostate cancer and stage III colon cancer. Age, race, sex, type of insurance, and comorbidity will be examined as predictors of the use of those treatments that are consistent with consensus guidelines. The investigators plan to use data from the CONCORD study to determine whether treatment factors are the reason for the reported differences between relative survival rates in the United States and Europe.

CONCLUSIONS

Results from the methodology used in the Patterns of Care study will provide, for the first time, detailed information about the quality and completeness of stage and treatment data that are routinely collected by states participating in the NPCR. It will add significantly to our understanding of factors that determine receipt of treatment in compliance with established guidelines. As part of the CONCORD study, it will also examine differences in survival among cancer patients with breast, prostate, and colon/rectum/anus cancers in the United States and Europe.

Cancer of the Uterine Cervix

HEALTH ISSUE: Cervical cancer is one of the most common malignant diseases of women; it is diagnosed in almost half a million women every year and half as many die from it annually. In Canada and other industrialized countries, its incidence has decreased due to cytology screening. However, invasive cases still occur, particularly among immigrant groups and native Canadian women. Although incidence of squamous cell carcinomas has decreased, the proportion of adenocarcinomas has increased because Pap cytology is ineffective to detect these lesions. KEY FINDINGS: In Canada, cervical cancer will cause an estimated 11,000 person-years of life lost. In most Canadian provinces, early detection is dependent on opportunistic screening. Primary prevention can be achieved through health education (sexual behavior modification) and vaccination to prevent infection from Human Papillomavirus (HPV). The initial results from vaccination trials are encouraging but wide scale use is more than a decade away. DATA GAPS AND RECOMMENDATIONS: Most cases of cervical cancer occur because the Pap smear was either false negative, was not done or not done often enough. Appropriate recommendations and guidelines exist on implementation of cytology-based programs. However, most Canadian women do not have access to organized screening. Further research is needed to 1) evaluate automated cytology systems; 2) define appropriate management of precursor lesions and 3) deliver definitive evidence of HPV testing efficacy in long-term follow-up studies with invasive cancer as an outcome and 4) provide Canadian data to justify augmenting or modifying current programs to use HPV testing in secondary triage of equivocal Pap smears.

Cervical cancer mortality by neighbourhood income in urban Canada from 1971 to 1996

BACKGROUND

The reduction of socioeconomic inequalities in health is an explicit objective of health policy in Canada, yet rates of death from cervical cancer are known to be higher among women of low socioeconomic status than among those of higher socioeconomic status. To evaluate progress toward the World Health Organization's goal of "Health for All," we examined whether income-related differentials in cervical cancer mortality diminished from 1971 to 1996.

METHODS

Death registration data for Canada's census metropolitan areas in 1971, 1986, 1991 and 1996 were assigned to census tracts through postal code, and the tracts were in turn assigned to income quintiles based on their proportion of the population below the Statistics Canada low-income cutoff values. We compared age-standardized death rates (using the 1966 world population standard) in the female population (excluding those in institutions) across the 5 income quintiles and calculated interquintile rate ratios (poorest over richest) and interquintile rate differences (poorest minus richest).

RESULTS

From 1971 to 1996, the overall age-standardized cervical cancer death rate per 100 000 women (and 95% confidence interval) declined from 5.0 (4.5-5.6) to 1.9 (1.7-2.1), the interquintile rate ratio diminished from 2.7 (1.8-4.2) to 1.7 (1.1- 2.6), and the interquintile rate difference decreased from 4.6 (2.8- 6.4) to 1.1 (0.2-1.9).

INTERPRETATION

The income-related disparity in rates of death from cervical cancer as measured by rate ratios and rate differences diminished markedly in urban Canada from 1971 to 1996. Among the numerous factors that may have contributed to the decline (including decline in fertility and improvement in diet), one important factor was probably the implementation of effective screening programs.

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.

Comparison of stomach cancer incidence and survival in four continents

The aim of this study was to compare stomach cancer incidence and survival rates between four very distinct areas: Campinas (Brasil), Latin America, Iowa (USA), Northern America, Varese (Italy), Europe and Osaka (Japan) in Asia, and determine which of the differences are due to variations in the case mix and which are due to the care received. A proportional hazards regression method was applied to the relative survival rates to obtain geographical differences that were adjusted for age, gender, period of diagnosis, sub-site and stage. Age, gender, period and stage explained most of the variability between the areas (50-100% excess risk of death with respect to Osaka) in the survival rates for stomach cancer patients. In Iowa and Varese, information on the sub-site fully explained the remaining variability. The large survival differences between the four areas were almost totally due to the different case mixes of the stomach cancer patients. The importance of stage indicates that diagnostic delay may be a major clinical factor affecting survival.

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.

Diabetes care in the U.S. and Canada

OBJECTIVE

To compare the glycemic control of patients with type 1 diabetes treated in the U.S. and Canada.

RESEARCH DESIGN AND METHODS

A large multicenter randomized clinical trial conducted in the U.S. and Canada was analyzed. Patients with type 1 diabetes, screened from 1983 to 1989 for enrollment in the Diabetes Control and Complications Trial (DCCT), were categorized as treated in the U.S. (n = 2,604) or Canada (n = 245). HbA(1c) levels were compared between U.S. and Canadian patients, both before and after adjustment for predictors of HbA(1c).

RESULTS

In general, volunteers screened for the DCCT were highly educated and following healthy lifestyles. Canadians were somewhat younger (25 vs. 27 years of age, P = 0.002), less likely to be college educated (62 vs. 71%, P = 0.002), more likely to receive care through a family doctor (41 vs. 28%, P = 0.001), and had a higher frequency of out-patient visits (4 vs. 3 per year, P = 0.004). Despite these differences in health care delivery, the mean HbA(1c) at baseline was identical in the two countries (8.9 vs. 9.0, P = 0.40). Adjustment for demographic, lifestyle, and clinical predictors of HbA(1c) yielded similar findings (9.0 vs. 9.2, P = 0.15). Equal percentages of American and Canadian patients who were screened ultimately entered the trial (21 vs. 19%, P = 0.20), and those randomized to conventional care achieved similar mean HbA(1c) levels (9.1 vs. 9.2, P = 0.50).

CONCLUSIONS

Differences in care delivery patterns do not yield large differences in glycemic control for patients with type 1 diabetes who were recruited in the U.S. and Canada for a large randomized trial.

Modifying a breast cancer risk factor survey for African American women

PURPOSE/OBJECTIVES

To evaluate a breast cancer risk factor survey for use with African American women.

DESIGN

Two focus groups consisting of women randomly selected from the patient population of Henry Ford Health System in Detroit, MI.

SETTING

A large, vertically integrated, private, nonprofit health system.

SAMPLE

Focus Group I consisted of 11 African American women aged 18-50, with a mean age of 41 years. Focus Group II consisted of nine African American women aged 51 and older, with a mean age of 60.9 years.

METHODS

A qualitative approach was used to gather and interpret the focus group data.

MAIN RESEARCH VARIABLES

Perceptions of a breast cancer risk factor survey and perceptions of breast cancer risk factors.

FINDINGS

The focus group participants suggested ways to improve the survey. Women in the younger age group appeared to lack awareness regarding breast cancer risk factors. Women in the older age group reported not knowing their family health histories.

CONCLUSIONS

Based on comments made by the focus group participants, the survey was modified substantially. Breast cancer risk factors were perceived differently by women in the two age groups.

IMPLICATIONS FOR NURSING

Results of a survey of a large, ethnically diverse sample of women could inform the development of culturally and age-appropriate nursing interventions designed to address breast cancer risk perceptions and enhance the likelihood of adherence to recommended mammography screening guidelines.

Impact of patient and provider characteristics on the treatment and outcomes of colorectal cancer

While the management and prognosis of colorectal cancer are largely dependent on clinical features such as tumor stage, there is considerable variation in treatment and outcome not explained by traditional prognostic factors. To guide efforts by researchers and health-care providers to improve quality of care, we review studies of variation in treatment and outcome by patient and provider characteristics. Surgeon expertise and case volume are associated with improved tumor control, although surgeon and hospital factors are not associated consistently with perioperative mortality or long-term survival. Some studies indicate that patients are less likely to undergo permanent colostomy if they are treated by high-volume surgeons and hospitals. Differences in treatment and outcome of patients managed by health maintenance organizations or fee-for-service providers have not generally been found. Older patients are less likely to receive adjuvant therapy after surgery, even after adjustment for comorbid illness. In the United States, black patients with colorectal cancer receive less aggressive therapy and are more likely to die of this disease than white patients, but cancer-specific survival differences are reduced or eliminated when black patients receive comparable treatment. Patients of low socioeconomic status (SES) have worse survival than those of higher SES, although the reasons for this discrepancy are not well understood. Variations in treatment may arise from inadequate physician knowledge of practice guidelines, treatment decisions based on unmeasured clinical factors, or patient preferences. To improve quality of care for colorectal cancer, a better understanding of mechanisms underlying associations between patient and provider characteristics and outcomes is required.

Cervical cancer: epidemiology, prevention and the role of human papillomavirus infection

Organized screening has contributed to a decline in cervical cancer incidence and mortality over the past 50 years. However, women in developing countries are yet to profit extensively from the benefits of screening programs, and recent trends show a resurgence of the disease in developed countries. The past 2 decades have witnessed substantial progress in our understanding of the natural history of cervical cancer and in major treatment advances. Human papillomavirus (HPV) infection is now recognized as the main cause of cervical cancer, the role of coexisting factors is better understood, a new cytology reporting terminology has improved diagnosis and management of precursor lesions, and specific treatment protocols have increased survival among patients with early or advanced disease. Current research has focused on the determinants of infection with oncogenic HPV types, the assessment of prophylactic and therapeutic vaccines and the development of screening strategies incorporating HPV testing and other methods as adjunct to cytology. These are fundamental stepping stones for the implementation of effective public health programs aimed at the control of cervical cancer.

Socioeconomic inequalities in cancer survival in England and Wales

BACKGROUND

Cancer survival often has been reported as lower for the poor than the rich, but, to the authors' knowledge, systematic national estimates of deprivation gradients in survival over long periods of time have not been available.

METHODS

The authors estimated national population-based survival rates for almost 3 million people who were diagnosed with 1 of 58 types of cancers (47 in adults, 11 in children) in England and Wales during the 20-year period 1971-1990 and followed through December 31, 1995. Cancer patients were assigned by their address at diagnosis to 1 of 5 categories (quintiles of the national distribution) of material deprivation by using a standard index derived from census data on unemployment, car ownership, household overcrowding, and social class that was available for all 109,000 census tracts in Great Britain. The authors used relative survival rates: the ratio of observed survival among the cancer patients to the survival that would have been expected if they had had the same background mortality as the general population. Background mortality differed widely among socioeconomic categories, and the authors constructed life tables from raw national mortality data by gender, single year of age, calendar period of death, and socioeconomic category to adjust for it. The authors used variance-weighted least squares regression to estimate both time trends in age standardized survival and socioeconomic gradients in survival. The number of avoidable deaths was estimated from the observed mortality excess compared with the expected mortality in each group of patients.

RESULTS

Survival rose steadily for most cancers over 25 years to 1995 in England and Wales, but inequalities in survival between patients living in rich and poor areas were geographically widespread and persistent over this period of time. These patterns existed for 44 of 47 adult cancers examined but not for 11 childhood cancers. These inequalities in survival represented more than 2500 deaths that would have been avoided each year if all cancer patients had had the same chance of surviving up to 5 years after diagnosis as patients in the most affluent group.

CONCLUSIONS

The largest national cancer survival study has provided strong evidence of systematic disadvantage in outcome among patients who lived in poorer districts compared with those who lived in wealthier districts.

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

OBJECTIVES

Comparisons of cancer survival in Canadian and US metropolitan areas have shown consistent Canadian advantages. This study tests a health insurance hypothesis by comparing cancer survival in Toronto, Ontario, and Honolulu, Hawaii.

METHODS

Ontario and Hawaii registries provided a total of 9190 and 2895 cancer cases (breast and prostate, 1986-1990, followed until 1996). Socioeconomic data for each person's residence at the time of diagnosis were taken from population censuses.

RESULTS

Socioeconomic status and cancer survival were directly associated in the US cohort, but not in the Canadian cohort. Compared with similar patients in Honolulu, residents of low-income areas in Toronto experienced 5-year survival advantages for breast and prostate cancer. In support of the health insurance hypothesis, between-country differences were smaller than those observed with other state samples and the Canadian advantage was larger among younger women.

CONCLUSIONS

Hawaii seems to provide better cancer care than many other states, but patients in Toronto still enjoy a significant survival advantage. Although Hawaii's employer-mandated health insurance coverage seems an effective step toward providing equitable health care, even better care could be expected with a universally accessible, single-payer system.

Associations between community income and cancer incidence in Canada and the United States

BACKGROUND

Associations between socioeconomic status (SES) and the incidence of cancer have been reported previously in the U.S. Canada has more comprehensive health care and social programs than the U.S. The purpose of this study was to compare the strength of associations between SES and cancer incidence in Canada and the U.S.

METHODS

The regions studied were the Canadian province of Ontario and the areas of the U.S. covered by the Surveillance, Epidemiology, and End Results (SEER) program. The populations at risk were defined using the 1991 Canadian Census and the 1990 U.S. Census. The populations of Ontario and of the SEER areas of the U.S. were each divided into deciles on the basis of median household income. Population-based cancer registries were used to identify incident cases. Age-standardized incidence rates for all major groups of malignant diseases were calculated for each SES decile in Ontario and in the U.S. Income-associated incidence gradients observed in Ontario and the U.S. were compared.

RESULTS

The incidence of most types of cancer was similar in Ontario and the U.S. In both countries, there were moderately strong, inverse associations between income level and the incidence of carcinomas of the cervix, the head and neck region, the lung, and the gastrointestinal tract. In both Ontario and the U.S., several of these diseases were twice as common in the bottom income decile than they were in the top decile. In contrast, carcinoma of the female breast and carcinoma of the prostate were more common among higher income communities in both countries, but the observed associations were weaker in Ontario.

CONCLUSIONS

Despite Canada's universal health insurance and more comprehensive social security system, the association between lower socioeconomic status and the incidence of many common cancers is just as strong in Ontario as it is in the U.S. The mechanisms responsible for these associations require further investigation.

Estimates of the lifetime direct costs of treatment for metastatic breast cancer

OBJECTIVE

Breast cancer remains the highest incident cancer among females in the United States and previous research suggests that a considerable portion of patients will eventually progress to the metastatic phase of the disease. This paper provides the first estimate of the lifetime direct costs of treating metastatic disease for one annual diagnostic cohort of breast cancer patients.

METHODS

Incidence rates were combined with US population counts to estimate the number of breast cancer cases diagnosed in 1994. Estimates of progression to metastatic disease (from Canadian provincial cancer registry data), costs of care (derived from patients' claims histories), survival (from SEER data), and national mortality rates (from US Census Bureau) were integrated, using Statistics Canada's Population Health Model (POHEM) to calculate lifetime costs.

RESULTS

This study estimates that more than 40% of the women diagnosed with breast cancer will progress to metastatic disease. On average, women with metastatic disease are expected to live 3 years and to incur direct treatment costs of approximately dollar 60,000 per case, resulting in a total lifetime cost for the cohort of almost dollar 4.2 billion.

CONCLUSIONS

The high rate of recurrence of breast cancer argues for the development of interventions that can prevent or delay the onset of metastatic disease. These estimates of lifetime costs and the methodology on which they are based can be used to evaluate the cost-effectiveness of such secondary prevention strategies. These estimates also can serve as a benchmark against which the lifetime costs of treating other diseases can be assessed.

Associations between community income and cancer survival in Ontario, Canada, and the United States

PURPOSE

The objectives of this study were as follows: (1) to compare the magnitude of the association between socioeconomic status (SES) and cancer survival in the Canadian province of Ontario with that in the United States (U.S.), and (2) to compare cancer survival in communities with similar SES in Ontario and in the U.S.

METHODS

The Ontario Cancer Registry provided information about all cases of invasive cancer diagnosed in Ontario from 1987 to 1992, and the Surveillance, Epidemiology and End Results Registry (SEER) provided information about all cases diagnosed in the SEER regions of the U.S. during the same time period. Census data provided information about SES at the community level. The product-limit method was used to describe cause-specific survival. Cox proportional hazards models were used to describe the association between SES and the risk of death from cancer.

RESULTS

There were significant associations between SES and survival for most cancer sites in both the U.S. and Ontario, but the magnitude of the association was usually larger in the U.S. In the poorest communities, there were significant survival advantages in favor of cancer patients in Ontario for many disease groups, including cancers of the lung, head and neck region, cervix, and uterus. However, in upper- and middle-income communities, there were significant survival advantages in favor of the U.S. for all cases combined and for several individual diseases, including cancers of the breast, colon and rectum, prostate, and bladder.

CONCLUSION

The association between SES and cancer survival is weaker in Ontario than it is in the U.S. This is due to a combination of better survival among patients in the poorest communities and worse survival among patients in the wealthier communities of Ontario relative to those in the U.S.