Regional variations in not treating diagnosed hypertension in Canada

Abstract

Improvements in the diagnosis and treatment of hypertension have been documented in Canada following implementation of a national program to improve hypertension management. To determine whether there are regional variations in not treating diagnosed hypertension with drugs in Canada. Using data from the Canadian Community Health Survey (CCHS) cycle 3.1 (2005), regional variation in drug treatment of diagnosed hypertension was examined. Also, national drug data from the Intercontinental Medical Statistics CompuScript database were analyzed to determine regional trends in total antihypertensive prescriptions in the period before and following the CCHS cycle 3.1. The overall rate of untreated hypertension among those diagnosed with hypertension in Canada was 12.7%. The highest untreated rate among those diagnosed with hypertension was in the Northern region (29.2%) and the lowest was in the Atlantic region (8.8%). Alberta (16.5%) and British Columbia (BC) (15.4%) also had higher untreated rates, while Ontario (13.2%) was similar to Canada overall. Younger age, single⁄never married status, larger household size, lack of access to a family physician and daily smoking were all associated with a higher likelihood of not receiving antihypertensive treatment. Adjusting for demographic characteristics, diagnosed hypertensive patients in Alberta (adjusted OR 1.35 [95% CI 1.14 to 1.61]) and BC (adjusted OR 1.64 [95% CI 1.40 to 1.91]) were more likely to be untreated than those in Ontario. The largest overall percentage increase in total antihypertensive prescriptions following the CCHS (ie, 2006) occurred in BC and Ontario. In Alberta, it remained almost unchanged and declined in Manitoba. Among adult Canadians diagnosed with hypertension, there were regional variations in the likelihood of not receiving antihypertensive therapy. Further research is required to understand the reasons for these variations to regionally target interventions and improve hypertension management in Canada.