Diagnosis and treatment of hypertension prior to and following introduction of a protocol

OBJECTIVE: To determine the compliance with and the outcome of a practice guideline introduced for the management of hypertension. DESIGN: Retrospective medical record survey. SETTING: The outpatient clinic of general internal medicine of the Academic Medical Hospital Nijmegen, the Netherlands. METHOD: Daily practice in a period before (1988) and one after (1993) implementation of the guideline were compared. By means of an inventory form we evaluated the compliance with the guideline, the decrease in blood pressure after 1 year's follow-up and the number and dosages of the prescribed drugs. Total costs were approximated from the number of visits and the number of laboratory and imaging evaluations. RESULTS: Compliance with the guideline in 1993 was 72% (24) compared with 65% (27) in 1988. This improvement was predominantly achieved by the junior residents. In 1993 in 15 patients (19%) blood pressure was measured without medication having been stopped. The guideline regarding the frequency of blood pressure measurement was observed in 7 patients (9%). The decrease in systolic and diastolic blood pressure was larger in 1993 than in 1988 (p < 0.05). This result was achieved by a larger number of blood pressure lowering drugs (1.40 (1.06) in 1993 vs. 1.17 (0.98) in 1988): the mean dose of the prescribed drugs was lower. The number of visits rose by 10% to 7.8 (3.7) and the number of diagnostic laboratory procedures by 25% to 956.