Changes in the rates of awareness, treatment and control of hypertension in Canada over the past two decades

Abstract

Background: Analyses of medication databases indicate marked increases in prescribing of antihypertensive drugs in Canada over the past decade. This study was done to examine the trends in the prevalence of hypertension and in control rates in Canada between 1992 and 2009.

Methods: Three population-based surveys, the 1986-1992 Canadian Heart Health Surveys, the 2006 Ontario Survey on the Prevalence and Control of Hypertension and the 2007-2009 Canadian Health Measures Survey, collected self-reported health information from, and measured blood pressure among, community-dwelling adults.

Results: The population prevalence of hypertension was stable between 1992 and 2009 at 19.7%-21.6%. Hypertension control improved from 13.2% (95% confidence interval [CI] 10.7%-15.7%) in 1992 to 64.6% (95% CI 60.0%-69.2%) in 2009, reflecting improvements in awareness (from 56.9% [95% CI 53.1%-60.5%] in 1992 to 82.5% [95% CI 78.5%-86.0%] in 2009) and treatment (from 34.6% [95% CI 29.2%-40.0%] in 1992 to 79.0% [95% CI 71.3%-86.7%] in 2009) among people with hypertension. The size of improvements in awareness, treatment and control were similar among people who had or did not have cardiovascular comorbidities Although systolic blood pressures among patients with untreated hypertension were similar between 1992 and 2009 (ranging from 146 [95% CI 145-147] mm Hg to 148 [95% CI 144-151] mm Hg), people who did not have hypertension and patients with hypertension that was being treated showed substantially lower systolic pressures in 2009 than in 1992 (113 [95% CI 112-114] v. 117 [95% CI 117-117] mm Hg and 128 [95% CI 126-130] v. 145 [95% CI 143-147] mm Hg).

Interpretation: The prevalence of hypertension has remained stable among community-dwelling adults in Canada over the past two decades, but the rates for treatment and control of hypertension have improved markedly during this time.

Figure 1:

Rates of hypertension awareness, treatment and control among Canadians with hypertension from 1992 to 2009. CHHS = Canadian Heart Health Survey, ON-BP = Ontario Survey on the Prevalence and Control of Hypertension, CHMS = Canadian Health Measures Survey.