Increases in antihypertensive prescriptions and reductions in cardiovascular events in Canada.

The Canadian Hypertension Education Program, an extensive professional education program to improve the management of hypertension, was started in 1999. There were very large increases in diagnosis and treatment of hypertension in the first 4 years after initiation of the program. The purpose of this study was to examine the association between the changes in antihypertensive therapy with changes in hospitalization and death from major hypertension-related cardiovascular diseases in Canada between 1992 and 2003. Using various national databases, Canadian standardized yearly mortality and hospitalization rates per 1000 for stroke, heart failure, and acute myocardial infarction were calculated for individuals aged >or=20 years and regressed against antihypertensive prescription rates. Changes in rates were examined in a time series analysis. There were significant reductions (P<0.0001) in the rate of death from stroke, heart failure, and myocardial infarction starting in 1999. There was also a reduction in hospitalization rate from stroke (P<0.0001) and heart failure (P<0.0001) but not myocardial infarction in 1999. The changes in death (P<0.001 for all 3 diseases) and hospitalization (P<0.0001 for stroke and heart failure; P=0.018 for acute myocardial infarction) were associated with the increases in antihypertensive prescriptions. This study demonstrates that the reduction in cardiovascular death and hospitalization rates is associated with an increase in antihypertensive prescriptions and that it coincides with the introduction of the Canadian Hypertension Education Program. The Canadian Hypertension Education Program educational model for improving health care could be adopted by other countries with well-developed professional and scientific societies.

Gender differences in colorectal cancer incidence, mortality, hospitalizations and surgical procedures in Canada.

BACKGROUND: Over the past few decades there have been changes in incidence and mortality of colorectal cancer. OBJECTIVE: To examine gender differences in incidence, hospitalization, hospital-based procedures and mortality for colorectal cancer. METHODS: Data were derived from the Hospital Morbidity Database, Canadian Cancer Registry and the Canadian Mortality Database. RESULTS: Overall incidence and mortality rates for colorectal cancer are decreasing, but remain substantially higher for males. Absolute numbers of cases are similar for men and women. The top subsite for men was rectal cancer, which was third highest for women, whereas right colon cancer was highest for women. Male/female ratios for incidence and surgeries were highest for distal cancer and are increasing with time. CONCLUSIONS: Although overall incidence rates have shown a decline, absolute numbers of new colorectal cancer cases have increased. While men have higher colorectal cancer rates, women have similar numbers and screening should target both equally. Over the years, colorectal cancer subsites are showing a rightward shift, i.e. an increase in proximal subsites, but a leftward shift in male/female ratios, i.e. a greater decrease for the more distal subsites in females. The lower rates for women for distal cancer are compatible with a degree of hormonal protection based on oral contraceptive and hormone replacement therapy. Colorectal cancer will continue to be a considerable public health problem in the foreseeable future.

The changing age distribution of prostate cancer in Canada.

BACKGROUND: Prostate cancer incidence rates are still increasing steadily; mortality rates are levelling, possibly decreasing; and hospitalization rates for many diagnoses are decreasing. Our objective is to examine changes in age distributions of prostate cancer during these times of change. METHODS: Prostate cancer cases were derived from the Canadian Cancer Registry, prostate cancer deaths from Vital Statistics, hospitalizations from the Hospital Morbidity File. Age-standardized rates were calculated based on the 1991 Canadian population. A prevalence correction for incidence rates was calculated. RESULTS: Age-specific incidence rates increased until 1995 for all ages, but a superimposed peak (1991-94) was greatest between ages 60-79. After 1995, increases in incidence continued for the under-70 age groups. Prevalence correction indicated the greatest underestimation of incidence rates for the oldest ages, but was less in Canada than in the United States. Mortality rates increased until 1994, then levelled and slowly decreased; age-specific mortality rates showed the greatest increase for the oldest ages but the earliest downturn for younger age groups. While hospitalizations dropped drastically after 1991, this drop was confined to elderly men (70+). CONCLUSIONS: Dramatic changes in age distributions of prostate cancer incidence, mortality and hospitalizations altered age profiles of men with prostate cancer. This illustrated the changing nature of prostate cancer as a public health issue and has important implications for health care provision, e.g., the increased numbers of younger new patients have different needs from the increasing numbers of elderly long-term patients who now spend less time in hospital.

Trends in prostate cancer incidence, hospital utilization and surgical procedures, Canada, 1981-2000.

BACKGROUND: Numbers of new prostate cancer cases in Canada continue to increase because of increasing prostate cancer incidence, population growth, aging of the population, and earlier detection methods such as PSA (prostate-specific antigen) testing. Concern has been expressed that PSA-related increases in incidence will make unaffordable demands on Canadian hospital resources. Our objective is to relate increases in prostate cancer incidence to trends in hospitalizations and in- patient treatment. METHODS: Hospitalizations with prostate cancer as primary diagnosis were obtained from the Hospital Morbidity Database, estimates of prostate cancer day surgery from the Discharge Abstract Database, newly diagnosed cases from the Canadian Cancer Registry, and prostate cancer deaths from the Vital Statistics Mortality Databases--all for the years 1981-2000. RESULTS: Between 1981-2000, the number of new cases rose from 7,000 to 18,500 with a transient peak, 1991-1994. Hospitalizations rose parallel to the incidence until 1991 but then fell sharply in spite of further increasing incidence. The use of radical prostatectomy (RP) increased steadily, but transurethral prostatectomy and bilateral orchiectomy decreased in the 1990s. Decreases in length of stay and in number of hospitalizations resulted in considerably decreased annual hospital days for all prostate cancer in-patient procedures except RP, which remained level since 1993. CONCLUSIONS: A net decrease in number of in-patient days occurred, despite the increasing number of new prostate cancer cases and the increasing use of radical prostatectomy. We concluded that increases in hospital utilization due to early detection programs, such as PSA testing, are unlikely to overwhelm in-patient services of Canadian hospitals.

Trends in in-patient hospital utilization and surgical procedures for breast, prostate, lung and colorectal cancers in Canada.

OBJECTIVE: To analyse population-based trends of in-patient surgical procedures for breast (female), prostate, lung and colorectal cancers. METHODS: The Hospital Morbidity Files supplied hospital data and the Canadian Cancer Registry, incidence data. Age-adjusted rates were standardized to the 1991 Canadian population. RESULTS: All four cancers showed major changes in trends of surgical procedures. For breast cancer, the rate of in-patient breast conservation surgery (BCS) increased from 1981 to the early 1990s while the rate of mastectomy decreased. Because day surgery was not included, the subsequent in-patient BCS rate stayed level. For prostate cancer, the rate of transurethral prostatectomy was initially high but decreased after 1990, while the rate of radical prostatectomy increased rapidly, only minimally affected by the PSA-related peak in incidence. The lung cancer lobectomy rate in men remained at 10/100,000 after 1986, but in women rose from 3/100,000 to 7/100,000, reflecting increasing lung cancer incidence. For colorectal cancer, right hemicolectomies and anterior resections increased, especially in men. CONCLUSIONS: Surgery trends reflected changes in incidence and treatment preferences. Canadian trends were generally similar to US trends, although the timing of some of the changes differed. Canadians tended to use less invasive procedures such as BCS and anterior resection.

Shorter hospital stays for breast cancer.

OBJECTIVES: This article examines trends in and factors influencing the length of stay for female breast cancer patients who were hospitalized between 1981 and 2000. DATA SOURCES: The hospital data are from the Hospital Morbidity Database and the Health Person-oriented Information Database, both maintained by Statistics Canada. Data on new cases of breast cancer are from the Canadian Cancer Registry and the National Cancer Incidence Reporting System. ANALYTICAL TECHNIQUES: Descriptive analyses present length of stayfor all hospital admissions with a primary diagnosis of breast cancer, by four-year period and by the patient's age, cancer stage, comorbid conditions and surgical procedures. Logistic regression is used to examine associations between these factors and length of stay. MAIN RESULTS: Since the early 1980s, the average length of stay in hospital for female breast cancer has fallen from 15.1 to 4.5 days. Declines occurred regardless of age group, cancer stage, procedure and comorbid conditions. Average stays first began to fall for less serious cases, but were eventually apparent for even the most serious.

Declining use of mastectomy for invasive breast cancer in Canada, 1981-2000.

OBJECTIVE: To evaluate the rate and magnitude of change in surgical practice for breast cancer in Canada in relation to publication dates of clinical trials and consensus conferences. METHODS: Hospital separations with a diagnosis of invasive breast cancer were extracted from the Hospital Morbidity File from 1981 to 2000. Age-standardized rates of in-patient procedures for breast-conserving surgery and mastectomy were analyzed by province and age group and by geographic region. RESULTS: In Canada, mastectomy rates decreased from 62.2 to 37.9 per 100,000 between 1981 and 2000; declines were largest between 1984 and 1985, following publication of the NSABP B-06 clinical trial in March 1985, and between 1991 and 1993, after the US NIH Consensus Conference in February 1991. Mastectomy rates plateaued between 1985 and 1991, and from 1993 to 2000; the transitory peak in 1988 corresponded to publicity surrounding Nancy Reagan's choice of mastectomy in 1987. Regional variations from the main pattern led to increasingly divergent mastectomy rates over time. Women aged 80+ were less likely to be treated by any surgery. INTERPRETATION: Publication of clinical trial results and consensus conferences were associated with changes in surgical treatment for breast cancer in Canada. However, divergent mastectomy rates among Canadian regions point to inconsistent adoption of less invasive therapy despite a publicly-funded health care system and national consensus guidelines.

Influenza vaccination.

OBJECTIVES: This article compares influenza vaccination rates in 1996/97 and 2000/01 and describes the characteristics of adults who were vaccinated. DATA SOURCES: The data on influenza vaccination are from the 1996/97 National Population Health Survey and the 2000/01 Canadian Community Health Survey, both conducted by Statistics Canada. Data on hospitalizations and deaths are from the Hospital Mortality Data Base and the Canadian Mortality Data Base, respectively. ANALYTICAL TECHNIQUES: Cross-tabulations were used to estimate rates of vaccination among seniors, people with chronic conditions, and the total population aged 20 or older. Multiple logistic regression was used to assess relationships between being vaccinated and selected characteristics. MAIN RESULTS: Between 1996/97 and 2000/01, the percentage of Canadians aged 20 or older who reported having had a flu shot the previous year rose from 16% to 28%. Rates were higher for seniors and people with chronic conditions. The odds of vaccination were high for residents of middle-to-high income households, people with at least some postsecondary education, former smokers, and people with a regular doctor. Smokers and people who reported their health as good to excellent had lower odds of being vaccinated.

Screening of infants and mortality due to neuroblastoma.

BACKGROUND: Neuroblastoma, the most common extracranial solid tumor that occurs in early childhood, can be identified in the preclinical stages by the detection of catecholamines in the urine. However, it is unknown whether routine screening for neuroblastoma reduces mortality due to this disease. METHODS: Through their parents, we offered screening for neuroblastoma at three weeks and six months of age to all 476,654 children born in the province of Quebec, Canada, during a five-year period (May 1, 1989, through April 30, 1994). The participation rate was 92 percent. The rate of death due to neuroblastoma was determined and compared with the rates in several unscreened control populations born during the same period. RESULTS: Among children younger than eight years of age in the Quebec cohort, there were 22 deaths due to neuroblastoma; the cumulative (+/-SE) mortality rate due to neuroblastoma was 4.78+/-1.14 per 100,000 children over a period of nine years. The standardized incidence ratios for death due to neuroblastoma for the Quebec cohort were 1.11 (95 percent confidence interval, 0.64 to 1.92) as compared with a control group in Ontario, Canada; 0.90 (95 percent confidence interval, 0.48 to 1.70) as compared with a control group in Minnesota; 1.40 (95 percent confidence interval, 0.81 to 2.41) as compared with a control group in Florida; and 0.96 (95 percent confidence interval, 0.56 to 1.66) as compared with a control group in the Greater Delaware Valley. The standardized mortality ratio for the Quebec cohort as compared with the rest of Canada was 1.39 (95 percent confidence interval, 0.85 to 2.30); the odds ratio for the comparison with a cohort born in Quebec before the screening program began was 0.98 (95 percent confidence interval, 0.54 to 1.77). CONCLUSIONS: Screening infants for neuroblastoma does not appear to reduce mortality due to this disease.