Decision rules for hypertension screening: application in a poor community with endemic hypertension.

Data from a hypertension screening project involving 4,272 black residents of a rural southern community were analyzed to determine the effects of a set of admission-decision rules on the case load of a proposed hypertension clinic. Four decision rules were investigated: conjunctive (diastolic high or systolic high); disjunctive (diastolic and/or systolic high); additive (sum of diastolic and systolic high); and systolic only. Most information relevant to admission to treatment came from knowledge of systolic blood pressures, even though knowledge of the diastolic pressure is essential in individual diagnosis. Incremental increases in the minimum blood pressure necessary for admission to treatment from 140/90 mm Hg to 160/95 mm Hg resulted in a one-third reduction in the number of patients treated, a 24% reduction in personnel utilization per patient, and a 34% reduction in drug costs; but in an estimated 14% increase in the attack rate for morbid events in men.