Analyses from SPRINT examine cost-effectiveness, patient-reported outcomes with intensive BP control

A recent analysis from SPRINT (Systolic Blood Pressure Intervention Trial) found that intensive blood pressure control appears more cost-effective than standard blood pressure control, while another SPRINT analysis found that intensive control appeared to have little effect on patient-reported outcomes.

In the first study, researchers used a microsimulation model to apply treatment effects and health care costs from SPRINT to a hypothetical cohort of patients who would have been eligible to participate. In SPRINT, patients assigned to a target systolic blood pressure below 120 mm Hg had lower rates of cardiovascular events than those assigned to a target below 140 mm Hg. In the current analysis, lifetime costs of treatment and monitoring for hypertension, cardiovascular disease events and costs of treatment, risk for serious adverse events related to treatment and costs, and quality-adjusted life-years (QALYs) were projected for intensive versus standard control of systolic blood pressure. The goal of the study was to compare the health benefits and costs over a lifetime for both types of blood pressure control.

The microsimulation model found that patients receiving intensive blood pressure control would have a mean number of QALYs that was 0.27 higher than patients receiving standard control. Intensive control would cost about $47,000 more per QALY gained than standard control if adherence and treatment effects decreased over the first five years. If the adherence and treatment effects lasted for the rest of the patient's lifetime, the cost would be about $28,000 more per QALY. Both of these values are below the standard willingness-to-pay thresholds of $50,000 per QALY and $100,000 per QALY. The researchers determined that intensive control stayed cost-effective regardless of whether treatment effects persisted in most of the simulation model's results.

The study results reflect a range of hypothetical treatment effects that go beyond the available SPRINT data, the authors wrote. In addition, among other limitations, their results may not apply to patients with a history of diabetes, stroke, or heart failure, since SPRINT excluded those patients. However, they concluded that intensive blood pressure control in their model appeared to be cost-effective for preventing cardiovascular disease events and extending lifespan.

The second study looked at patient-reported outcomes from SPRINT and compared those in the intensive treatment group with those in the standard treatment group. Outcome measures were scores on the Physical Component Summary (PCS) and Mental Component Summary (MCS) of the Veterans RAND 12-item Health Survey, the Patient Health Questionnaire 9-item depression scale (PHQ-9), satisfaction with blood pressure care and medications, and adherence to blood pressure medications. The researchers compared scores on these measures between the intensive treatment and standard treatment groups for all participants and for participants stratified by physical and cognitive function.

Those in the intensive treatment group had a systolic blood pressure that was 14.8 mm Hg lower at 12 months versus the standard treatment group (121.4 mm Hg vs. 136.2 mm Hg, respectively). The two treatment groups did not differ in mean PCS, MCS, and PHQ-9 scores over follow-up for all participants or for participants according to physical and cognitive function at baseline. At 12 months, 88.6% of the intensive treatment group and 88.2% of the standard treatment group said they were satisfied or very satisfied with their hypertension care. Adherence to hypertension medication did not differ significantly between groups (44.4% adherence overall).

The researchers noted that their study might have missed negative effects of intensive treatment on patient-reported outcomes if they occurred early. In addition, they pointed out that because SPRINT was terminated early, long-term follow-up data were missing for many participants, among other limitations. However, they concluded that intensive blood pressure control had little effect on patients' self-reported outcomes and adherence and did not appear to be linked to decreased physical or mention function or to depressive symptoms.

“Translating the current findings into clinical practice presents a challenge and would result in changes in how clinicians manage hypertension in older patients. Before patients and clinicians adopt such changes, they will need to be reassured that intensive treatment not only reduces the risk of cardiovascular events and death, but will result in few side effects as shown in patient-reported assessments,” they wrote. “The current results provide complementary evidence that supports the main findings of our trial.”

Both studies were published Aug. 24 by the New England Journal of Medicine.