Objectives: To discuss changes during the past decades in the prevalence and in the patterns of detection, treatment and control of arterial hypertension in the general Belgian population aged 25-64 years.
Design: Data from two cross-sectional cardiovascular disease risk factor surveys of the general population aged 25-64 years during the first and second halves of the 1980s (the Belgian Inter-university Research on Nutrition and Health study of 1980-1984 and the World Health Organization Multinational Monitoring of Trends and Determinants in Cardiovascular Diseases study of 1985-1992) are compared.
Participants: Age-stratified and sex-stratified random samples from the general population yielded 9372 participants in the former study and 4904 participants in the latter.
Methods: In both studies, blood pressure measurements and other variables were collected in the same standardized way and by the same observers.
Results: For both sexes, overall age-standardized prevalences of hypertension (subjects with systolic blood pressure > or = 160 mmHg or diastolic blood pressure > or = 95 mmHg or currently being administered antihypertensive drug treatment) were found to be significantly (P< 0.001) higher in the former than they were in the latter study. A significant decline in population mean systolic blood pressure values was observed for both sexes on going from the former data to the latter (falls of 6.0 and 7.3 mmHg for men and women, respectively, P< 0.01). In log-linear models, adjusted for age, a highly significant (P< 0.0001) favourable shift in the population distribution over the various categories of detection, treatment and control of hypertension was observed. This trend exhibited a significant sex difference, however, there being a much more favourable trend for women.
Conclusions: In Belgium, favourable trends in the prevalence and in the patterns of detection, treatment and control of arterial hypertension and in the levels of systolic blood pressure were observed. The so-called 'rule of halves' is no longer valid.