Prevalence and control of hypertension in an Ontario county.

A survey of a representative population sample was carried out to evaluate the prevalence and control of hypertension in Middlesex County, Ontario. Of the 3067 subjects selected 2735 completed the initial interview. If the diastolic blood pressure was greater than 89 mm Hg in three readings, up to two further visits were made. The prevalence rate of hypertension in the sample was estimated to be 115/1000. Only 5.1% of the hypertensive subjects were unaware of their condition, and 5.4% were aware but not receiving treatment. In 16.9% the hypertension was treated but uncontrolled, while in 72.6% it was treated and controlled. The prevalence rate was significantly higher in the older subjects (p less than 0.0001). Control was better in the women and the older subjects. The results indicate that physicians in Middlesex County are detecting and treating most patients with hypertension; screening programs are thus not needed. Control of hypertension could be further improved by determining why the condition in those receiving treatment is not being controlled.