Changes in blood pressure and antihypertensive treatment in a community over four years.

In 1971 persons aged 50 to 59 years in Albury were screened for hypertension and those with diastolic blood pressure equal to or over 110 mm Hg were notified. On screening of the sample in 1975, the proportion of persons receiving treatment had doubled to 22%. Most of those newly receiving treatment in 1975 had had diastolic blood pressures under 110 mm Hg in 1971. The mean systolic and diastolic pressures of the newly treated group had fallen by 13-7 and 9-1 mm Hg respectively to 153-5 and 91-6 mm Hg. The mean pressures of subjects already receiving treatment in 1971 and continuing it remained higher (163-1 mm Hg systolic and 100-9 mm Hg diastolic), despite their receiving relatively more medication. The latter group was composed of patients likely to have had more severe hypertension originally, and the importance of effective treatment for them is emphasized. The frequency with which subjects with mild hypertension are being treated demonstrates the urgent need to complete randomized controlled trials of treatment in this group.