Hypertension and the probability of an incapacitating event over a defined period: impact of treatment.

(1) The risks of coronary heart disease, cerebrovascular disease and all-cause mortality associated with increasing levels of pressure are graded and continuous from the lowest to the highest levels. (2) Data from several large prospective studies allow evaluation of individual risk based on blood pressure level but may require modification in the context of aircrew. (3) Because cardiovascular risk factors appear to interact and 'cluster' in hypertensives, a broadened approach to the evaluation of risk for the individual and the management of hypertension is necessary and appropriate. (4) Anti-hypertensive treatment has been shown in trials to reduce the incidence of stroke but appears much less effective at reducing coronary events. It may be that a management policy which involves an assessment of and intervention on all risk factors together, incorporating the use of anti-hypertensive drugs which do not have adverse metabolic effects will be more effective in this context. Evaluation of such a policy in a long-term morbidity and mortality trial is however urgently required.