Evaluation of a computer-based decision support system for treatment of hypertension with drugs: retrospective, nonintervention testing of cost and guideline adherence.

OBJECTIVE: To evaluate a computerized decision support system (DSS) for drug treatment of hypertension, regarding quality, safety, and cost compared to actual antihypertensive drug treatment.
DESIGN: The medical profiles of 338 hypertensive patients treated with drugs against hypertension were processed by the DSS. The drug treatment proposed by the system was then compared to actual treatment given by their physician.
SETTING: Four health centres in the county of Västerbotten, in Sweden.
SUBJECTS: A list of hypertensive patients was extracted from the computerized medical records of each health centre and every fifth patient's medical profile was assessed by the system.
INTERVENTIONS: None. MAIN OUTCOME MEASURES: Drug used, drug used in relation to certain major diseases such as diabetes mellitus, asthma, ischaemic heart disease (IHD), and previous myocardial infarction. Adherence to hypertension guidelines, safety, and cost.
RESULTS: The DSS suggested significantly more thiazides and significantly fewer calcium antagonists than the physicians had prescribed, with a total cost reduction of 33-40%, depending on doses chosen. The DSS drug profile was more adherent to guidelines in patients with major complicating diseases, suggesting an improvement in treatment quality for these patients by the DSS.
CONCLUSION: The DSS which fully implements current guidelines may improve the quality of antihypertensive treatment, concurrently leading to a considerable reduction in drug costs.