Hypertension registers in general practice: levels of control and nondrug management.

Sixty-five general practitioners throughout Northland agreed to establish and maintain hypertension registers for a three year trial period beginning in 1982. Opportunistic blood pressure screening was undertaken of all patients aged 20-69 attending practices for whatever reason. Patients with an average of six readings on at least three separate occasions which exceeded WHO criteria for hypertension (diastolic blood pressure greater than 95 mmHg and/or systolic blood pressure greater than 160 mmHg) were entered onto the registers as were patients already receiving antihypertensive drugs. In all 3703 patients were registered. The percentage exceeding WHO criteria fell from 49.4% to 38.8% for those followed up for twelve months and from 48.6% to 34.5% for those followed up for twenty-four months. The percentage with diastolic blood pressure less than 90 mmHg increased significantly for each follow up group and with length of follow up. Overall 8.2% at entry were managed without drugs, for those followed up for thirty months this fell to 6.2% with individual practice percentage varying from nil to over twenty. There appears scope to manage between 10-20% of hypertensives without drugs.