Monitoring performance for blood pressure management among patients with diabetes mellitus: too much of a good thing?

Abstract

Performance measures that reward achieving blood pressure (BP) thresholds may contribute to overtreatment. We developed a tightly linked clinical action measure designed to encourage appropriate medical management and a marker of potential overtreatment, designed to monitor overly aggressive treatment of hypertension in the face of low diastolic BP. We conducted a retrospective cohort study in 879 Department of Veterans Affairs (VA) medical centers and smaller community-based outpatient clinics. The clinical action measure for hypertension was met if the patient had a passing index BP at the visit or had an appropriate action. We examined the rate of passing the action measure and of potential overtreatment in the Veterans Health Administration during 2009-2010. There were 977,282 established VA patients, 18 years and older, with diabetes mellitus (DM). A total of 713,790 patients were eligible for the action measure; 94% passed the measure (82% because they had a BP <140/90 mm Hg at the visit and an additional 12% with a BP ≥140/90 mm Hg and appropriate clinical actions). Facility pass rates varied from 77% to 99% (P < .001). Among all patients with DM, 197,291 (20%) had a BP lower than 130/65 mm Hg; of these, 80 903 (8% of all patients with DM) had potential overtreatment. Facility rates of potential overtreatment varied from 3% to 20% (P < .001). Facilities with higher rates of meeting the current threshold measure (<140/90 mm Hg) had higher rates of potential overtreatment (P < .001). While 94% of diabetic veterans met the action measure, rates of potential overtreatment are currently approaching the rate of undertreatment, and high rates of achieving current threshold measures are directly associated with overtreatment. Implementing a clinical action measure for hypertension management, as the Veterans Health Administration is planning to do, may result in more appropriate care and less overtreatment.