CMAJ: Canadian hypertension control improves, prevalance remains stable
Hypertension control and treatment has improved substantially over a 25-year span in Canada, but prevalence of the condition has remained stable among adults, according to research published May 16 in the Canadian Medical Association Journal.

“Elevated blood pressure is the most important modifiable risk factor for vascular disease and mortality in developed nations,” Finlay A. McAlister, MD, of the division of general internal medicine at the University of Alberta in Edmonton, Canada, and colleagues wrote. “There is a strong log-linear relationship between blood pressure levels and vascular outcomes, and there is robust evidence from randomized trials showing that reducing blood pressure can prevent cardiovascular events (particularly stroke).”

McAlister et al evaluated three Canadian studies—1986-1992 Canadian Heart Health Surveys (CHHS), ON-BP (2006 Ontario Survey on the Prevalence and Control of Hypertension) and CHMS (2009 Canadian Health Measures Survey)—that measured blood pressure (BP) control rates and hypertension between 1992 and 2009 to understand whether the changes seen within hypertensive patients in Ontario were representative to the rest of the world.

Results showed that the population prevalence of hypertension was stable between 1992 and 2009 at 19.7 percent to 21.6 percent.

In 1992, 2006 and 2009, the population prevalence of hypertension was reported to be 21.6 percent, 21.3 percent and 19.7 percent, respectively. Between 1992 and 2009, hypertension control improved from 13.2 percent to 64.6 percent. McAlister et al noted that improved awareness increased from 56.9 percent to 82.5 percent in 2009. Additionally, treatments improved from 34.6 percent in 1992 to 79 percent in 2009 among hypertensive patients.

The researchers found that the proportion of Canadians with hypertension whose blood pressure was under control and below 140/90 mm Hg increased from 13.2 percent in 1992 to 64.6 percent in 2009. The number of patients who were unaware of hypertension declined from 43.2 percent to 17.4 percent from 1992 to 2009, respectively.

“The management of hypertension among community-dwelling Canadian adults appears to have improved over the past two decades,” the researchers wrote.

“Finally, among people with hypertension, those who also had cardiovascular or cerebrovascular disease were more likely to have their blood pressure under control,” the authors wrote. “This is encouraging, as it suggests that either Canadian physicians appropriately target more intensive therapy to patients at higher risk or that patients at higher risk are more compliant with their therapy.”

The authors wrote that efforts should continue to focus on the optimization of the management of hypertension to reduce cardiovascular disease in Canada. “Moreover, without continued vigilance and reinforcement after improvements in practice have been made, quality of care will deteriorate over time,” they concluded.