Using personal health insurance numbers to link the Canadian Cancer Registry and the Discharge Abstract Database.

BACKGROUND: Linking cancer registry and administrative data can reveal health care use patterns among cancer patients. The Canadian Cancer Registry (CCR) contains personal health insurance numbers (HINs) that facilitate linkage to hospitalization information in the Discharge Abstract Database (DAD). DATA AND METHODS: Valid HINs, captured in the CCR or obtained through probabilistic linkages to provincial health insurance registries, were used to deterministically link prostate, female breast, colorectal and lung cancers diagnosed from 2005 through 2008 with the DAD for fiscal years 2004/2005 to 2010/2011. RESULTS: At least 98% of tumours diagnosed from 2005 through 2008 had valid HINs in the CCR or obtained through probabilistic linkages. For provinces submitting day surgeries to the DAD, linkage rates to at least one DAD record were higher for female breast (95.6% to 98.1%), colorectal (96.9% to 98.7%) and lung cancers (92.8% to 96.3%) than for prostate cancers (77.2% to 91.6%). Among linked records, agreement was high for sex (99% or more) and complete date of birth (97% or more); the likelihood of a consistent diagnosis in the CCR and on at least one linked DAD record was higher for female breast (86.8% to 97.2%), colorectal (94.6% to 97.7%) and lung cancers (90.3% to 95.5%) than for prostate cancers (77.4% to 87.8%). INTERPRETATION: Deterministically linking the CCR and DAD using personal HINs is a feasible and valid approach to obtaining hospitalization information about cancer patients.

Trends in postacute myocardial infarction management and mortality in patients with diabetes. A population-based study from 1995 to 2001.

OBJECTIVE: To compare trends in coronary revascularization use and case fatality rate (CFR) following acute myocardial infarction in patients with and without diabetes. METHODS: A retrospective study of 77,552 patients, 20 years of age or older (25% with diabetes), who were hospitalized for a first acute myocardial infarction in the province of Quebec between April 1995 and December 2001 was conducted. Administrative databases were used to identify patients and assess outcomes. RESULTS: Compared with patients without diabetes, patients with diabetes underwent more coronary artery bypass graft (CABG) surgeries (11.1% versus 8.3%; P<0.0001) but fewer percutaneous coronary interventions (17.1% versus 20.2%; P<0.0001). The use of percutaneous coronary intervention increased substantially over time in both populations, driven mainly by an increase during the index admission (20.6% versus 16.6% per year; P=0.1144 in patients with and without diabetes, respectively). The use of CABG during the index admission increased markedly among patients with diabetes compared with those without (10.3% versus 5.3% per year; P=0.0072); however, at one-year following discharge, CABG use remained stable in patients with diabetes and fell in those without (-0.7% versus -5.3% per year; P=0.2046). Concomitantly, patients with diabetes presented a similar decline in CFR compared with patients without diabetes. The decline was more pronounced during the index admission (-5.0% versus -4.1% per year; P=0.282) than at one-year following discharge (-2.5% versus -2.5% per year; P=0.629) in patients with and without diabetes, respectively. However, fatal outcome remained higher in patients with diabetes than without, with an adjusted RR of 1.21 (95% CI 1.18 to 1.24) at one-year follow-up. CONCLUSION: Overall, coronary revascularization use and CFR improved over time in patients with diabetes. Nevertheless, the mortality rate in patients with diabetes remains higher than in patients without diabetes, indicating that additional progress is required to improve the poorer prognosis in this population.

Cardiovascular burden and related risk factors among Nunavik (Quebec) Inuit: insights from baseline findings in the circumpolar Inuit health in transition cohort study.

BACKGROUND: The Inuit are commonly portrayed to be somehow protected from cardiovascular diseases (CVDs) through their traditional lifestyle and diet. However, actual sociocultural transition and related major, modifiable risk factors have scarcely been quantified in the Inuit population. Such knowledge is extremely valuable in terms of public health intervention. METHODS: A total of 887 Inuit residents from Nunavik, Quebec, participated in a cohort study. The estimates presented were derived from anthropometric and biological measurements gathered at the time of recruitment and enhanced by information collected in the medical file of each participant. All estimates were corrected for a complex sampling strategy and bootstrapped to ensure the representativeness of the general Nunavik population. RESULTS: Overall, 19% of Inuit had a disease of the circulatory system according to the International Statistical Classification of Diseases and Related Health Problems, 10th revision. Among all disorders, peripheral circulatory system disease was the most prevalent (9%). Prevalences of ischemic heart disease and cerebrovascular disease were of similar magnitude (2.5%). No significant difference in disease prevalence was noted between sexes. The major modifiable CVD risk factors were smoking (84%), obesity (49%) [corrected] (body mass index of greater than 30 kgm2) and elevated blood pressure (13085 mmHg or greater) (18%). Prevalences were globally higher among women. CONCLUSION: The current belief that the Inuit are protected from CVD is seriously questioned by the results of the present study. Considering the extremely high prevalence of CVD risk factors, a population-based intervention reinforced for women is urgently needed to reduce their risk.

Cancer among the circumpolar Inuit, 1989-2003. I. Background and methods.

OBJECTIVES: This is first of 2 papers on the Circumpolar Inuit Cancer Review, an international collaborative effort involving researchers and health officials from Alaska, Canada and Greenland. It covers the period 1989-2003, updating the last review (1969-1988) and together provides an overview of the trends and patterns of cancer among the Inuit in 3 countries and over a 35-year period. METHODS: Inuit cancer cases by age-sex group and anatomic site were obtained from the regional cancer registries. The sources of the age-sex distribution of various Inuit populations include the population registry (Greenland), and annual estimates and periodic censuses (Alaska and Canada). Incidence rates were age-standardization by the direct method to the standard world population of the International Agency for Research on Cancer. CONCLUSIONS: This project demonstrates the feasibility of international partnerships in cancer surveillance, and when these partnerships are extended to other diseases and health conditions, they can contribute to the development of a Circumpolar Health Observatory.

Cancer among the circumpolar Inuit, 1989-2003. II. Patterns and trends.

OBJECTIVES: This is the second of 2 papers reporting on the result of the Circumpolar Inuit Cancer Review, an international collaborative effort involving researchers and health officials from Alaska, Canada and Greenland. METHODS: Inuit cancer cases by age-sex group and anatomic site were obtained from the regional cancer registries. RESULTS: Cancer in general is increasing among Inuit, in all regions, and among both men and women. Inuit continue to be at extreme high risk, relative to non-Inuit and to comparisons of global populations, for the historically recognized so-called traditional cancers (such as cancer of the nasopharynx and salivary glands). Among the so-called modern cancers prevalent in developed societies, lung cancer is rapidly increasing in incidence (especially in Canada), such that the rate in both Inuit men and women is the highest in the world; other cancers, such as colorectal cancer, are also on the rise (especially in Alaska), while breast and prostate cancer remain low relative to the non-Inuit population. The decline in cervical cancer is a positive development; in the 3 regions, the rate in Greenland is the highest. CONCLUSIONS: Data such as these can form the basis of interventions directed towards known risk factors such as smoking, diet, obesity, viral and bacterial infections, and low screening prevalence. Cancer surveillance is a basic task of the public health system; in the Arctic, it is particularly important as Inuit continue to undergo further changes in their life-styles and social environments.

Trends in cancer prevalence in Quebec.

Cancer prevalence is of prime interest in public health because of its use in estimating the disease's burden on the heath care system. This study's objective was to estimate five-year prevalence of tumours from 1989 to 1999 and ten-year prevalence of tumours from 1994 to 1999 in the Province of Quebec (Canada). Five-year prevalence was used to represent tumours for which people are more likely to obtain primary treatment; ten-year prevalence included those tumours in addition to tumours that can be considered cured but still need follow-up. Information was extracted from the Quebec Cancer Registry. Prostate cancer was the most prevalent malignancy among males (25 percent, five-year prevalent tumours), while breast cancer was most prevalent among females (38 percent, five-year prevalent tumours). For both sexes, the greatest observed prevalence increase was for endocrine glands. On average, five-year prevalence proportions were 16 percent higher in men than in women; those of ten year were 14 percent higher in men. Furthermore, the largest differences were observed for bladder and lung cancer. The change in cancer prevalence in Quebec was dependent on the tumour site.