Hypertension control at the work site. Comparison of screening and referral alone, referral and follow-up, and on-site treatment.

Four methods for improving hypertension control among employees were tested in one manufacturing plant each: screening and referral to a physician but no other intervention; referral to a physician and semiannual follow-up; referral to a physician and more frequent follow-up as needed; and on-site treatment or care by a family physician. All methods significantly increased the proportion of subjects under treatment, but only the three programs offering follow-up or treatment significantly improved the adequacy of control. At the end of the three years of the project, 56 to 62 per cent of the hypertensive employees in these three programs had blood-pressure readings below 140/90 mm Hg, and 86 to 90 per cent had readings below 160/95. In contrast, among employees who received no intervention after screening, only 21 per cent had readings below 140/90 mm Hg at the end of the study, and only 47 per cent had readings below 160/95. Employees selecting on-site treatment had the highest level of blood-pressure control, but this finding appeared to be due to self-selection of previously untreated patients into on-site treatment and to exclusion of employees with other medical problems. We conclude that work-site hypertension programs can produce substantial improvements in blood-pressure control if they include systematic, routine follow-up that provides employees with information about their condition and offers support for maintenance of therapy.