Objective: To study the test-ordering behavior of practicing physicians regarding ambulatory monitoring of blood pressure and to assess changes in patient management after this study.
Design: Cross-sectional assessment of physicians' practice habits regarding the ordering of ambulatory blood pressure monitoring and a longitudinal study of patient management after monitoring.
Setting: Physicians' offices in central Connecticut.
Participants: Two hundred thirty-seven consecutive patients referred by 65 community- and hospital-based physicians.
Measurements: Indications for ambulatory blood pressure monitoring, changes in diagnosis and therapy, and office blood pressures before and after the ambulatory blood pressure study.
Results: The main indications for ordering the test included borderline hypertension (27% of studies ordered), assessment of blood pressure control during drug therapy (25%), evaluation for "white coat" or "office" hypertension (22%), and drug-resistant hypertension (16%). After the ambulatory blood pressure study, only 13% of the patients had further testing (for example, echocardiography); the diagnosis was changed in 41% of the patients, and antihypertensive therapy was changed in 46%. In 122 patients for whom data were complete, office blood pressure measured by the referring physician decreased from 161/96 +/- 22/12 mm Hg before the ambulatory blood pressure study to 151/86 +/- 27/12 mm Hg 3 months after the study (P = 0.004 for systolic blood pressure and P < 0.001 for diastolic blood pressure). One to 2 years after the study, office blood pressure was 149/86 +/- 24/12 mm Hg (P > 0.2 compared with 3 months after the study). Seventy-two percent of the patients had a lower office blood pressure within 3 months of the ambulatory blood pressure study.
Conclusions: Practicing physicians use ambulatory blood pressure recordings for appropriate indications, and data from the monitoring studies affected the management of patients with hypertension.