Jay Onysko

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 ≥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.

Large Increases in Hypertension Diagnosis and Treatment in Canada After a Healthcare Professional Education Program

This study was conducted to compare the self-reported prevalence and treatment of hypertension in adult Canadians before and subsequent to the implementation of the Canadian Hypertension Education Program in 1999. Data were obtained from 5 cycles of the Canadian Health Surveys between 1994 and 2003 on respondents aged ≥20 years. Piecewise linear regression was used to calculate the average annual increase in rates, before and after 1999. Between 1994 and 2003, the percentage of adult Canadians aware of being diagnosed with hypertension increased by 51% (from 12.37% to 18.74%; P<0.001), and the percentage prescribed antihypertensive drugs increased by 66% (from 9.57% to 15.86%; P<0.001). After 1999, there was approximately a doubling of the annual rate of increase in the diagnosis of hypertension (from 0.52% of the population per year before 1999 to 1.03% per year after 1999; P<0.001) and the percentage prescribed antihypertensive drugs (from 0.54% of the population per year before 1999 versus 0.98% per year after 1999; P<0.001). The proportion of those aware of the diagnosis of hypertension but not being treated with drugs was reduced by half between 1994 and 2003 (from 31.47% untreated to 15.34% untreated; P<0.001). There was a greater increase in awareness of hypertension and use of antihypertensive drugs among men compared with women after 1999. The large increase in the diagnosis and treatment of hypertension in Canada between 1994 and 2003 is consistent with an overall beneficial effect of the Canadian Hypertension Education Program, including a reduced gender gap in hypertension care.

Reduced cervical cancer incidence and mortality in Canada: national data from 1932 to 2006

BackgroundHigh levels of participation in cervical screening are reported in Canada from the 1970’s as a result of early uptake of the Pap smear and universal Medicare. Despite recommendations to the contrary, the programs have featured early age of initiation of screening and frequent screening intervals. Other countries have achieved successful outcomes without such features. We analyzed national data to better understand mortality and incidence trends, and their relationships to screening.MethodsThe Canadian Cancer Registry, National Cancer Incidence Reporting System, and the Canadian Vital Statistics Database were used to measure mortality and incidence rates. Cases and deaths from invasive cervical cancer were classified by 5 year age groups at diagnosis and death (15 to 19 years through to 80 to 84 years), year of diagnosis (1972 to 2006), and year of death (1932 to 2006). Probabilities of developing and dying from cervical cancer were calculated for age-specific mortality and incidence. The proportion of women reporting a timely Pap test was estimated for 1978 to 2006.ResultsCervical cancer mortality has declined steadily from a peak of 13.5 to 2.2 per 100,000 (83%,) between 1952 and 2006, and 71% between 1972 and 2006. Incidence of invasive cervical cancer has declined by 58% since 1972. These declines have occurred more among older age groups than younger. Invasive cervical cancer incidence and mortality is less in each successive birth cohort of women. Participation rates in screening are high especially in women under age 50.ConclusionsDespite increasing risk factors for cervical cancer, both incidence and mortality have declined over time, across age groups, and across birth cohorts. Earlier increasing mortality (1932 – 1950) was likely related to improved classification of cancers and the early subsequent reduction (1950 – 1970) to improved treatment. Recent improvements in incidence and mortality are likely due to high rates of screening. For women under age 30 years there are low rates of disease but lesser improvement related to screening.

The Outcomes Research Task Force and the Canadian Hypertension Education Program

The present report is an update on the contribution of the Canadian Hypertension Education Programs (CHEP) Outcomes Research Task Force to the surveillance and monitoring efforts surrounding hypertension and hypertension-related conditions in Canada. Components of the program include advocating national physical measures surveys of blood pressure; analysis of national cross-sectional and longitudinal population-based health surveys that assess hypertension diagnosis and treatment; assessment of national and regional pharmacotherapy patterns using existing commercial databases; assessment of national and regional trends in hypertensive complications (stroke, myocardial infarction and congestive heart failure); development of a national system based on provincial administrative data to assess the incidence, prevalence and management of diagnosed hypertension; and assessing some aspects of CHEP implementation. Preliminary data support a large increase in the diagnosis and treatment of hypertension corresponding to the initiation of CHEP.

Changes in cardiovascular deaths and hospitalization in Canada

Cardiovascular disease is the leading cause of death and disability in Canada (1,2). The increasing age of our population and unhealthy eating habits are associated with increases in obesity, diabetes and hypertension. This has led to dire predictions of increases in deaths and hospitalizations from cardiovascular disease, and has enormous implications for health care resource allocation (2). Globally, increases in cardiovascular disease have led to predictions that cardiovascular disease will be the leading cause of death and disability around the world within 20 years (3). Some have predicted that the steady progress toward increased longevity will be reversed by our currently unhealthy lifestyles (4). In contrast with our lifestyles, advances have been made in medical therapies to prevent cardiovascular death and disability. These advances have been seen in both primary and secondary prevention. Further, our understanding of knowledge translation on prevention and treatment of cardiovascular disease has significantly advanced. Forums on cardiovascular health promotion have repeatedly stated that cardiovascular disease is largely preventable (4,5,6). The Canadian Hypertension Education Program (CHEP) was developed to improve the management of hypertension and, hence, prevent cardiovascular events. As part of the CHEP, there is ongoing monitoring of deaths and hospitalization from stroke, congestive heart failure and acute myocardial infarction. Many of the analyses are in progress but in this editorial, we report the crude unadjusted mortality and hospitalization rates for these conditions. To our surprise, we found that since the late 1990s, there has been a decline in the total number of deaths from cardiovascular disease and specifically, stroke and congestive heart failure, both of which were rising earlier in the 1990s (Figure 1). Deaths from acute myocardial infarction have been declining throughout the 1990s (Figure 1). Further, there has been a decline in total hospitalizations for stroke and congestive heart failure since the late 1990s (Figure 2). Changes in coding for acute myocardial infarction currently make interpretation of our administrative data on hospitalization for acute myocardial infarction unreliable. Figure 1 The total number of deaths per month in Canada from stroke, congestive heart failure, acute myocardial infarction and cardiovascular disease. The data points represent the unadjusted number of deaths in Canada per month, while the line represents the ... Figure 2 The total number of hospitalizations per month in Canada from stroke and congestive heart failure. The data points represent the unadjusted number of hospitalizations per month in Canada, while the line represents the moving six-month average number of ... The declines in death and hospitalization represent a huge Canadian success story. Secondary prevention is likely a partial reason for the decline. In-hospital mortality from cardiovascular diseases has decreased from 9.6% in 1994/1995 to 8.4% in 2001/2002 (1). There have been improvements in utilization of beta-blockers, angiotensin-converting enzyme inhibitors, statins and antiplatelet drugs following acute myocardial infarction (7). System changes to support increased cardiac and stroke rehabilitation, as well as chronic congestive heart failure care, have been implemented in some locations and can reduce death and disability (8–12). Primary prevention is also a likely reason for the decline. In the United Kingdom, prevention of coronary mortality was predominantly due to improved prevention (7). The numbers of patients hospitalized for cardiovascular diseases were also reduced, supporting improved prevention (1). Reductions in smoking and large increases in the use of statins, and in particular antihypertensive therapies, have occurred and would be expected to reduce event rates (2,13–15). The observational nature of the data preclude cause and effect conclusions, but further refined analysis using adjusted data and time series analysis are planned. What are the implications? First, we think a very brief pause to celebrate is required because we have an interlude in the previous steady increases in cardiovascular death and hospitalization. The data are encouraging that a much broader, more extensively resourced effort supported by extensive system change to implement proven therapies in treatment and prevention will further reduce death, disability and more costly health care resource usage. These Canadian data suggest that applying resources to the prevention of cardiovascular death and disability is fruitful, even in a country with one of the lowest cardiovascular disease rates (4). However, we must remain cautious in our enthusiasm. Canada has an aging population, poor dietary habits prevail, there has not been a large increase in physical activity, obesity is increasing, and it is very likely that the prevalence of hypertension and diabetes is increasing (16,17). These trends could lead to increases in death and disability from cardiovascular disease and speak strongly to the need to address diet, physical activity and obesity with population health strategies. Enhanced surveillance will allow for more insights into the successes and gaps in preventing cardiovascular death and disability and will support the development of more focused programs to address these increasing risks to our health.

Invasive cervical cancer incidence and mortality among canadian women aged 15 to 29 and the impact of screening.

OBJECTIVE The utility of screening young women for cervical cancer is questionable given the likelihood of pre-cancer regression and the potential harm of the intervention. Our objective was to determine the incidence and mortality rates of invasive cervical cancer (ICC) in women aged 15 to 29 years and to assess changes in rates since the uptake of screening. METHODS The incidence of ICC cases from 1970 to 2007 was obtained from records in the Canadian Cancer Registry and from the National Cancer Incidence Reporting System. Mortality rates in women with ICC for the same time period were obtained from the Canadian Vital Statistics Death Database. Data were classified by age group and year at diagnosis or death, assessed at five-year intervals. The incidence was further analyzed according to histology. RESULTS ICC among 15- to 19-year-olds is rare and has remained relatively constant from 1970-1974 to 2005-2007. From 1975-1979 to 2005-2007, the incidence in 20- to 24-year-olds declined from 3.2 to 1.2 per 100 000. From 1980-1984 to 2005-2007, the incidence in 25- to 29-year-olds declined from 11.1 to 6.3 per 100 000. Deaths among 15- to 19-year-olds and 20- to 24-year-olds are rare, but in 25- to 29-year-olds mortality declined from 0.9 to 0.5 per 100 000 between 1975-1979 and 2005-2007. Among 20- to 24-year-olds, rates of all cervical cancers and squamous cell carcinomas declined, while adenocarcinomas and unknown types were rare. In 25- to 29-year-olds there was a decline in all cervical cancers and squamous cell cancers and an apparent increase in adenocarcinoma. CONCLUSIONS ICC in adolescents is rare and does not justify population-based screening. Screening appears to have affected the incidence of ICC in 20- to 24-year olds and incidence and mortality from ICC in 25- to 29-year-olds.

The Influence of Breast Self-Examination on Subsequent Mammography Participation

OBJECTIVES We evaluated whether breast self-examination (BSE) influences subsequent mammography participation. METHODS We evaluated associations between BSE and subsequent mammography participation, adjusting for baseline screening behaviors and sociodemographic, health, and lifestyle characteristics, among women aged 40 years and older using data from the longitudinal Canadian National Population Health Survey. RESULTS Regular performance of BSE at baseline was not associated with receipt of a recent mammogram at follow-up among all women (adjusted odds ratio [OR]=1.01; 95% confidence interval [CI]= 0.75, 1.35) or with mammography uptake among the subgroup of women reporting never use at baseline (adjusted OR=0.78; 95% CI=0.50, 1.22). CONCLUSIONS The lack of association between performance of BSE and subsequent mammography participation suggests that not recommending BSE is unlikely to influence mammography participation.

Childhood cancer incidence in Canada: demographic and geographic variation of temporal trends (1992–2010)

INTRODUCTION Surveillance of childhood cancer incidence trends can inform etiologic research, policy and programs. This study presents the first population-based report on demographic and geographic variations in incidence trends of detailed pediatric diagnostic groups in Canada. METHODS The Canadian Cancer Registry data were used to calculate annual age-standardized incidence rates (ASIRs) from 1992 to 2010 among children less than 15 years of age by sex, age and region for the 12 main diagnostic groups and selected subgroups of the International Classification of Childhood Cancer (ICCC), 3rd edition. Temporal trends were examined by annual percent changes (APCs) using Joinpoint regression. RESULTS The ASIRs of childhood cancer among males increased by 0.5% (95% confidence interval (CI) = 0.2-0.9) annually from 1992 to 2010, whereas incidence among females increased by 3.2% (CI = 0.4-6.2) annually since 2004 after an initial stabilization. The largest overall increase was observed in children aged 1-4 years (APC = 0.9%, CI = 0.4-1.3). By region, the overall rates increased the most in Ontario from 2006 to 2010 (APC = 5.9%, CI = 1.9-10.1), and increased non-significantly in the other regions from 1992 to 2010. Average annual ASIRs for all cancers combined from 2006 to 2010 were lower in the Prairies (149.4 per million) and higher in Ontario (170.1 per million). The ASIRs increased for leukemias, melanoma, carcinoma, thyroid cancer, ependymomas and hepatoblastoma for all ages, and neuroblastoma in 1-4 year olds. Astrocytoma decreased in 10-14 year olds (APC = -2.1%, CI = -3.7 to -0.5), and among males (APC = -2.4%, CI = -4.6 to -0.2) and females (APC = -3.7%, CI = -5.8 to -1.6) in Ontario over the study period. CONCLUSION Increasing incidence trends for all cancers and selected malignancies are consistent with those reported in other developed countries, and may reflect the changes in demographics and etiological exposures, and artefacts of changes in cancer coding, diagnosis and reporting. Significant decreasing trend for astrocytoma in late childhood was observed for the first time.