THE INTERVENTION EFFECTS OF A COMMUNITY-BASED HYPERTENSION CONTROL PROGRAM IN 2 RURAL SOUTH-AFRICAN TOWNS - THE CORIS STUDY

The objective of the hypertension programme of the Coronary Risk Facto r Study (CORIS) was to evaluate the effectiveness of the first 4 years of community-based intervention. The hypertension intervention model comprised a blood pressure station where the whole population was scre ened for hypertension, nondrug management was provided and hypertensiv es were monitored after referral to general practitioners for drug the rapy. Two levels of intervention were maintained: in the high-intensit y intervention town (N = 2 278) hypertensives were actively followed u p, and in the low-intensity intervention town (N = 2 620) no active fo llow-up procedure existed. A third town acted as control (N = 2 290). In the cohort which was hypertensive at baseline, the net decreases in systolic blood pressure (mean +/- SE) after correction for changes in the control town were 0,5 +/- 2,2 mmHg (men) and 4,5 +/- 2,2 mmHg (wo men) in the low-intensity intervention town, and 5,6 2,3 mmHg (men) an d 7,5 +/- 2,2 mmHg (women) in the high-intensity intervention town. Th e net decrease in diastolic blood pressure was 3,4 +/- 1,2 mmHg (men) and 4,4 +/- 1,1 mmHg (women) in the low-intensity intervention town, a nd 6,1 +/- 1,2 mmHg (men) and 5,9 +/- 1,1 mmHg (women) in the high-int ensity intervention town. These reductions were statistically signific ant with one exception. The changes in the total population in the 3 c ommunities after 4 years of intervention were similar to those found i n the hypertensive cohort. Decreases in mean blood pressure were accom panied by marked increases in the proportion of hypertensives on drug treatment and the proportion under control (< 160/95 mmHg). Distributi on curves of blood pressure indicated a large effect in the subgroup a bove the cut-off point for hypertension; however, the entire curve als o shifted to the left, indicating, in addition, benefit to the whole p opulation. An increase in the appropriate knowledge and action for hyp ertension control was observed in the intervention towns compared with the control town. The CORIS community-based hypertension control prog ramme successfully reduced the risk for cardiovascular diseases in the intervention towns compared with the control town.