Maxing Out BP Meds in Diabetics Questioned
Overly aggressive treatment of hypertension in diabetic patients occurred almost as often as undertreatment at facilities included in a review of Veterans Affairs (VA) hospitals and outpatient clinics.
Overall, 94% of hypertensive diabetic patients seen at 879 VA facilities received care consistent with a clinical action measure of appropriate treatment of hypertension. However, 20% of patients had lower-than-recommended blood pressure values, and examination of records revealed potential overtreatment in 40% of the cases (8% of all diabetic patients).
Rates of overtreatment ranged as high as 20% at individual facilities, particularly facilities that achieved high rates of compliance with threshold blood pressure values, according to an article published online in Archives of Internal Medicine.
“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,” Eve A. Kerr, MD, of the VA Ann Arbor Healthcare System and University of Michigan in Ann Arbor, and co-authors wrote.
“Implementing a clinical measure for hypertension management, as the Veterans Health Administration is planning to do, may result in more appropriate care and less overtreatment.”
Treat-to-target has become the clinical mantra for controlling cardiovascular risk factors, particularly lipids and blood pressure. However, dichotomous threshold measures (such as blood pressure
<140/90 mm Hg) fail to take into account individual variation in risk, patient preferences, treatment intensity, disease severity, or adherence, the authors explained.
Moreover, available evidence has not consistently supported a treat-to-target strategy. Randomized trials have shown causal associations between treatment and benefit, but not achievement of a specific threshold for a risk factor.
"Dichotomous threshold measures, however, are silent on the manner of achieving risk factor control," the authors continued. "Consequently, such measures can promote overtreatment and diastolic hypotension, which has been shown in multiple studies to be associated with worse cardiovascular outcomes."
In contrast, "tightly linked" clinical action measures based on evidence better reflect the complexities and nuances of clinical decision making in the treatment of hypertension. Clinical action measures do not focus solely on attainment of a risk factor level but also the implementation of evidence-based treatment when a risk factor threshold is not attained.
In collaboration with the Department of Veterans Affairs, the authors developed a clinical action measure for blood pressure management. They also identified a marker of potential overtreatment that could result in a patient receiving overly aggressive, risky treatment.
The clinical action measure consisted of four criteria for appropriate care:
Blood pressure <140/90 mm Hg Blood pressure <150/65 mm Hg Systolic blood pressure <150 mm Hg in patients receiving three or more appropriately dosed antihypertensives Appropriate action within 90 days meets the definition of appropriate care Potential overtreatment was defined as blood pressure <130/65 mm Hg in a patient taking three or more medications or who is on active medication intensification. Data from 879 VA medical centers and community-based outpatient clinics revealed 977,282 established patients (ages 18 to 75) with diabetes between 2009 and 2010. Of those, 713,790 were eligible for the action measure. Overall, 94% of patients received treatment in accordance with the measure: 82% as a result of blood pressure <140/90 mm Hg at the index visit, and 12% with higher blood pressure but appropriate clinical action to meet the measure. Rates of adherence to the clinical measure ranged from 77% to 99% among the 879 facilities (P<0.001). The authors found that 197,291 diabetic patients had blood pressure <130/65 mm Hg. Within that subgroup, 80,903 patients met the definition of overtreatment. Among individual facilities, rates of potential overtreatment ranged from 3% to 20% (P<0.001). The authors found a significant association between high rates of adherence to the threshold measure and higher rates of potential overtreatment (P<0.001). The authors cautioned that the action measure may have underestimated the true rate of appropriate care because they were not able to assess medications prescribed outside of the VA or contraindications to treatment other than low diastolic levels. The finding that 94% of diabetic patients met the clinical action measure for blood pressure "is an outstanding accomplishment," Eileen Handberg, PhD, of the University of Florida in Gainesville, wrote in a commentary. Nonetheless, performance measure definitions provide reasons for concern. Handberg said one concern is the lack of consistency between the performance measure and clinical guideline recommendations, specifically the Seventh Report of the Joint National Committee recommendations and the hypertension management guidelines developed by the American Diabetes Association. A second concern relates to the authors' definition of overtreatment. The definitions are based on the authors critique of current research in hypertension management in patients with diabetes, but not the guidelines in place when the patients' blood pressure was assessed. "Because there is no reporting of increased risk and no clear understanding of the complexity of comorbidities, a blanket statement that 10% of the VA population may be overtreated creates a negative impression that might not be true," Handberg wrote. "The reporting of performance measures is important, and the development of tightly linked clinical measures as those by Kerr et al is an important step forward in evaluating the complexities of management for hypertension and serve as a model for other measures," she added. "However, reporting and evaluating performance measures must ensure that performance is linked to guidelines at the time of performance."