The efforts by the Veterans Administration (VA) to ensure that all hypertensive diabetic patients receive appropriate blood-pressure medication has been so successful that many patients may be "overtreated," results of a new study show .
The study by Dr Eve Kerr (Department of Veterans Affairs, Ann Arbor Healthcare System, MI) and colleagues, published online May 28, 2012 in the Archives of Internal Medicine, shows that the VA has made impressive progress in reducing undertreatment of hypertension in diabetic patients at its hospitals. But it now "appears that in the VA, rates of potential overtreatment are currently approaching, and perhaps even exceeding, the rate of undertreatment and that high rates of achieving current performance measurement targets are directly associated with medication escalation that may increase risk for patients," the authors conclude.
Kerr et al retrospectively analyzed the care of hypertension in nearly a million established VA patients with diabetes at 879 VA hospitals and smaller outpatient clinics in 2009 and 2010. The measures taken to manage the hypertension in each patient was considered appropriate if the patient did not have high blood pressure (<140/90 mm Hg) during the index visit or if the patient's hypertension was treated appropriately with blood-pressure medication.
In the study, 82% of patients had a blood pressure <140/90 mm Hg and 12% of patients with a higher blood pressure were treated with appropriate clinical actions, according to Kerr et all, so 94% of patients "passed" the test of the study. However, pass rates varied among facilities from 77% to 99% (p<0.001). Among all of the patients with diabetes, 20% had blood pressure below 130/65 mm Hg, and therefore 8% of patients with diabetes were potentially overtreated, the study found. Facility rates of potential overtreatment varied from 3% to 20% (p<0.001), and the facilities with the highest rates of meeting the threshold target of <140/90 mm Hg had higher rates of potential overtreatment (p<0.001).
According to the authors, recent improvements in treatment of diabetic patients have been partially driven by performance measures focused on specific risk-factor thresholds. "Yet, the evidence does not fully support the 'treat-to-target' approach implied in current performance measures," Kerr et al argue. "While there is no doubt that appropriate management of hypertension among patients with diabetes is of critical importance, our data suggest that the VA and other high-performing health systems may have reached the point when threshold measures for BP control have the potential to do more harm than good," Kerr et al explain.
"Most randomized controlled trials provide causal evidence for the benefit of treatment (eg, a BP medication or statin) and not a particular threshold risk-factor level achieved in the intervention group," Kerr et al. explain. "Consequently, such measures can promote overtreatment and diastolic hypotension, which has been shown in multiple studies to be associated with worse cardiovascular outcomes."
Instead of these dichotomous thresholds, the study authors favor "tightly linked" clinical action measures strongly tied to the evidence. The VA is now instituting new clinical action measures for hypertension management that capture the complexity of clinical decisions, credit the facility for delivering the right evidence-based treatment even if a specific risk-factor threshold is not achieved, and reduce the potential for overtreatment and unintended consequences accounting for other patient-specific factors.
In an accompanying editorial , Dr Eileen Handberg (University of Florida, Gainesville) argues that Kerr et al's definition of "overtreatment" is based on their critique of current hypertension management research and not guidelines that were available to the VA clinicians evaluated by the study. "With no guidance as to a lower threshold other than epidemiological (for BP) and other risk-factor (for LDL-cholesterol) data that 'lower is better,' one could argue that lower BPs were an indicator of better care, not 'overtreatment,' " Handberg argues. The study presents no evidence that these "overtreated" patients were at increased risk, so "a blanket statement that 10% of the VA population may be overtreated creates a negative impression of care that might not be true."
Nevertheless, Handberg agrees that "reporting of performance measures is important, and the development of tightly linked clinical measures as those by Kerr et al are an important step forward in evaluating the complexities of management for hypertension and serve as a model for other measures."
Neither the authors nor the editorialist have any financial disclosures.