Heart attacks more likely among lower-income groups, but quality of care about the same for all Canadians

Variations in heart attack and hysterectomy rates much greater by region than by socio-economic status

What: Health Indicators 2010

May 27, 2010—Canadians living in the least-affluent neighbourhoods are more likely to have a heart attack than those in more-affluent areas, according to a new report released today by the Canadian Institute for Health Information (CIHI). Canadians living in low-income neighbourhoods have higher rates of hypertension, diabetes, smoking and other cardiac risk factors. However, heart attack patients receive about the same quality of care across the country, regardless of their socio-economic status.

The report, Health Indicators 2010, provides more than 40 measures of health and health system performance in Canada for larger health regions, provinces and territories. This year’s report includes a special focus on disparities by socio-economic status, through the analysis of two common reasons for hospitalizations in Canada—acute myocardial infarctions (AMIs), commonly known as heart attacks, and hysterectomies.

In 2008–2009, almost 67,000 Canadians were hospitalized for a heart attack. After breaking down the Canadian population into five neighbourhood income levels, the report found that Canadians living in the least-affluent neighbourhoods were 37% more likely to have a heart attack than those in the most-affluent areas: 255 per 100,000 population versus 186 per 100,000, respectively. However, the report found that differences in treatment and quality of care for heart attacks were small or insignificant between socio-economic groups.

For example

• Heart attack patients from the most-affluent neighbourhoods were 7% more likely to get a revascularization procedure, such as angioplasty or bypass surgery, than those from the lowest-income neighbourhoods. Medical literature indicates that not every patient is selected for or would benefit from such a procedure.
• The risk of dying in hospital within 30 days of being admitted for a heart attack was about the same for all socio-economic groups, averaging 8.3%. Hospital mortality risk is a measure of quality of care.
• The risk of an unplanned readmission to hospital after a heart attack was slightly higher for patients from the least-affluent neighbourhoods, at 5.2%, compared to a 4.7% risk for patients from the most-affluent neighbourhoods. This indicator may reflect quality of care in hospital as well as after discharge.

“Identifying and measuring disparities in our health care system can help identify areas of potential concern and where to focus improvement efforts,” explains Indra Pulcins, Director of Indicators and Performance Measurement at CIHI. “It is reassuring to see that in our universal system, the quality of care is similar for all heart attack patients. However, important gaps in heart health still exist between socio-economic groups, as well as between geographic regions in Canada. Addressing these gaps could help improve the health of the population.”

Regional and socio-economic disparities impact health, health care costs

CIHI’s study found that differences in heart attack rates were larger between geographic regions than between neighbourhood income quintiles. For example, rates of heart attacks varied more than threefold between health regions in Canada and more than twofold between provinces. In 2008–2009, heart attack rates varied from 347 per 100,000 in Newfoundland and Labrador and 294 per 100,000 in Prince Edward Island to 205 per 100,000 in Alberta and 169 per 100,000 in British Columbia, after population age differences across provinces were taken into account.

“While a person’s socio-economic status affects the risk of having a heart attack, it appears that where you live in Canada makes a bigger difference,” explains Eugene Wen, Manager of Health Indicators at CIHI. “Regions with higher heart attack rates also tend to have higher rates of hypertension, diabetes, smoking and other cardiac risk factors.”

CIHI’s data also shows that reducing regional and socio-economic differences in heart attack rates could significantly lower the number of heart attacks in Canada and possibly result in considerable cost savings. For example, if in 2008–2009 all socio-economic groups had had the same heart attack rate as those from the most-affluent neighbourhoods, the overall rate of hospitalized heart attacks would have decreased by approximately 16%, or the equivalent of about 10,400 hospitalized heart attacks. Based on 2007–2008 cost data, this represents an estimated potential savings in hospital costs of about $100 million, not including physician fees.

Similarly, if in 2008–2009 all provinces had had the same heart attack rate as British Columbia, the province with the lowest rate of heart attacks in that time period, there would have been about 15,500 fewer hospitalized heart attacks, representing a potential decline of 22% in the national heart attack rate. This would have generated an estimated potential savings of about $150 million in hospital costs, not including physician fees.

Hysterectomy rates are declining but vary between urban and rural settings

Hysterectomy is the second most common surgery for Canadian women, after Caesarean sections (C-sections), and this year’s report found hysterectomy rates continued to decline. In 2008–2009, close to 47,000 women had a hysterectomy, representing an age-standardized rate of 338 hysterectomies per 100,000 women age 20 and older. While some disparities existed in hysterectomy rates across neighbourhood income levels, the study showed they were not as substantial as the varying rates between the provinces.

For example, hysterectomy rates were lower in the least- and most-affluent neighbourhoods, compared to the middle-income neighbourhoods. However, rates varied even more across the provinces: from 512 per 100,000 in Prince Edward Island and 421 per 100,000 in Newfoundland and Labrador to 319 per 100,000 in Quebec and 311 per 100,000 in British Columbia, after population age differences across provinces were taken into account.

The variations in hysterectomy rates were also much more pronounced between urban and rural areas in Canada than between socio-economic levels. In 2008–2009, the hysterectomy rate was 46% higher for women from rural settings than urban ones.

Menstrual disorders were the main reason for hysterectomies in rural areas. The age-standardized rate for hysterectomies due to menstrual disorders among rural women was more than double the rate among urban women: 135 per 100,000 and 66 per 100,000, respectively. Uterine fibroids topped the list for women in urban areas.

“The differences in hysterectomy rates for menstrual disorders between urban and rural Canada may point to differences in clinical practice, rather than health differences,” explains Dr. Vyta Senikas, Associate Executive Vice-President of the Society of Obstetricians and Gynecologists of Canada (SOGC). “Menstrual disorders include irregular or abnormal levels of bleeding, pain, etc. While hysterectomies may be necessary, there are other less-invasive treatment options that may not be as widely available to women in rural areas.”

Other highlights from the Health Indicators report include the following:

• The increasing trend of C-section rates started to slow down.
• From 2000–2001 to 2005–2006, the national rate of C-section deliveries as a proportion of hospital births rose from more than one in five births (21.4%) to more than one in four births (26.3%). As of 2005–2006, the increase in rates started to slow down, reaching 26.9% by 2008–2009. Dr. Senikas comments, “While the decreasing trend for C-sections is encouraging and heading in the right direction, continued efforts to lower these rates are needed to achieve even more dramatic results.”
• Rates of in-hospital mortality and readmissions after heart attacks continued to decline across Canada. These indicators measure quality of care for heart attack patients.
• Between the periods 2003–2004 to 2005–2006 and 2006–2007 to 2008–2009, the rate of in-hospital death following a heart attack decreased from 10.3% to 8.9%.
• Rates for readmission after a heart attack between the periods 2003–2004 to 2005–2006 and 2006–2007 to 2008–2009 declined from 6.2% to 4.7%.
• However, mortality and readmission rates continued to vary across Canada between provinces and health regions, reflecting opportunities for improvement.

About CIHI

The Canadian Institute for Health Information (CIHI) collects and analyzes information on health and health care in Canada and makes it publicly available. Canada’s federal, provincial and territorial governments created CIHI as a not-for-profit, independent organization dedicated to forging a common approach to Canadian health information. CIHI’s goal: to provide timely, accurate and comparable information. CIHI’s data and reports inform health policies, support the effective delivery of health services and raise awareness among Canadians of the factors that contribute to good health.

Media contacts:

Leona Hollingsworth
416-549-5213
lhollingsworth@cihi.ca

Angela Baker
416-549-5402
Cell: 416-459-6855
anbaker@cihi.ca

Figures

• Figure 1. Age-Standardized Rates of Hospitalized Acute Myocardial Infarction Events by Province/ Territory, Canada, 2008–2009 (Figure 1 in the report)
• Figure 2. Age-Standardized Rates of Hospitalized Acute Myocardial Infarction Events by Neighbourhood Income Quintile and Sex, Canada, 2008–2009 (Figure 2 in the report)
• Figure 3. Age-Standardized Hysterectomy Rates by Province/Territory, Canada, 2008–2009 (Figure 7 in the report)
• Figure 4. Age-Standardized Hysterectomy Rates by Indication and Urban/Rural Dwelling, Canada, 2008–2009 (Figure 9 in the report)