1. A study was conducted amongst 1247 treated hypertensive patients to determine the predictive power of untreated baseline and achieved treated blood pressures in the development of the complications of hypertension. In addition the relative importance of systolic and diastolic pressures was calculated.
2. Statistical analysis was done by calculating univariate differences in blood pressure between cases with and without complications. The higher the univariate distance, the greater the predictive power.
3. Blood pressures achieved during treatment were more important than baseline pressures for predicting stroke in both men and women, confirming the benefits of antihypertensive therapy in preventing strokes.
4. There was some evidence of prevention of myocardial infarction in men and of angina in women as a result of therapy.
5. There was no evidence to suggest that any one group of drugs, including β-adrenoreceptor-blocking drugs and thiazides, conferred any extra benefit in preventing coronary heart disease.
6. The systolic blood pressures achieved during treatment predicted stroke better than diastolic pressure, but no consistent trends were found for coronary heart disease.