Lessons from worldwide experience with hypertension control.

Control of hypertension encompasses primary prevention, early detection and adequate treatment of high blood pressure. Primary prevention involves action at the community level to reduce obesity, alcohol and salt consumption, and increase physical activity. Management of hypertension involves diagnostic work-up, assessment of overall CVD risk, nonpharmacological and pharmacological treatment. The concept of community control was introduced to WHO's cardiovascular programme in the late 1960s, with hypertension as a spearhead. Once it had been demonstrated that the community approach was feasible, activities were extended to other cardiovascular, and later to noncommunicable, diseases. Outcome and process evaluations were made. A decrease in mortality and morbidity from stroke and myocardial infarction was demonstrated in most studies. As a result of these programmes, hypertension awareness, treatment and control rates increased remarkably and mean blood pressure levels decreased. The WHO/WHL Hypertension Management Audit Project attempted more complex analyses in various European populations. The majority of community control programmes emphasized detection and treatment, rather than primary prevention. Therefore, despite a decline in age-adjusted average blood pressures in various populations, the incidence of hypertension did not follow this trend. The decline observed in average blood pressure was achieved mainly by widespread drug treatment. Since cardiovascular risk grows with increasing blood pressure continuously and progressively, events occurring in the "normotensive' blood pressure range escape control. Developing countries will encounter the problem of prohibitive costs of care and drug treatment for hypertension. Therefore greater emphasis must be put on primary prevention in community control programmes.