BP Management in Patients with Diabetes

Among patients with diabetes mellitus (DM), cardiovascular risk factors include high lipid levels and elevated blood pressure (BP). There has been significant improvement in the control of these factors over the past decade, an improvement driven in part by performance measurement that focuses on achieving specific risk factor thresholds.

Current threshold measures suggest that risk factor levels should be below a certain target in the majority of patients, regardless of underlying cardiovascular risk, patient preference, intensity of treatment, underlying severity of disease, or regimen adherence. According to researchers, available evidence does not support this treat-to-target approach; the majority of randomized controlled trials identify causal evidence for the benefit of treatment and not a particular threshold risk factor level achieved in the intervention group.

Noting the possibility that performance measures that reward achievement BP thresholds may contribute to overtreatment, the researchers collaborated with clinical and operations leaders in the Department of Veterans Affairs (VA) to specify a clinical action measure for BP management in patients with DM. They also specified a marker of potential hypertension overtreatment to assess the proportion of patients who may be receiving overly aggressive and, according to the researchers, “overly risky” treatment. Results of the retrospective cohort study were reported in Archives of Internal Medicine [2012;(172(12):938-945].

The study was conducted in 879 VA medical centers and smaller community-based outpatient clinics. Participants met the clinical action measure for hypertension if they had a passing index BP at the visit or had an appropriate action. The researchers measured the rate of passing the action measure and of potential overtreatment in the VA from 2009 to 2010.

Of the 977,282 VA patients ³18 years of age with DM, 713,790 were eligible for the action measure. Of those, 82% (n=583,338) had a BP of <140/90 mm Hg at the visit and 12% (n=84,872) had a BP of ³140/90 mm Hg and appropriate clinical actions. Of the patients 18 to 75 years of age, 94% passed the measure. Men were slightly more likely to meet the measure than women (94% vs 93%; P<.001). Patients with ischemic heart disease (IHD) were also more likely to meet the measure compared with those without IHD (95% vs 93%; P<.001). There was modest variation across the 879 facilities in predicted probability of meeting the measure (range, 77%-99%; P<.001).

Analyses designed to identify potential overtreatment found that 20% (n=197,291) of the entire cohort had a BP <130/65 mm Hg; of those, 80.903 were potentially overtreated. Among the patients in the potentially overtreated group, mean systolic BP was 114.5 mm Hg and mean diastolic BP was 57.6 mm Hg. Patients in this group were older, had lower mean index BP, were more likely to be men, and were more likely to have IHD.

There were 263,492 patients who were ³76 years of age; of those, 30% had a BP  <130/65 mm Hg and 40% were potentially overtreated (12% of all patients with DM who were ³76 years of age). The effect of age and the presence of IHD were independent predictors of overtreatment.

Using a 2-level model, the researchers determined that a 55-year-old patient without IHD had a predicted probability of overtreatment of 3.8%, whereas an 80-year-old patient with IHD had a predicted probability of overtreatment of 15.3%.

There was variation by facility in predicted probability of overtreatment for patients ³18 years of age (range 3% to 20%). Facilities with higher rates of meeting the current threshold measure (<140/90 mm Hg) had higher rates of potential overtreatment (P<.001).

In conclusion, the researchers commented that, “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.”