Rigorous interventions to control blood pressure add months to a patient’s life without prohibitive health or financial costs, according to a study co-authored by Christiana Care Health System scholars and published Aug. 24 in the New England Journal of Medicine (NEJM).
By connecting a health intervention with both cost-effectiveness and health benefits, the study helps Christiana Care and other health systems transition to value-based care, said Zugui Zhang, Ph.D, a lead biostatistician and Value Institute scholar, who co-authored the paper along with former Cardiology chief and researcher William Weintraub, M.D., MACC, FAHA, FESC.
The Systolic Blood Pressure Intervention Trial, or SPRINT, weighed the costs and benefits of aggressive treatment of blood pressure. It took into account the financial cost of such treatment and the risks of serious side effects it might cause.
The team’s findings amount to an endorsement of more intensive blood-pressure treatment in the target population, which on average added more than three months of healthy life compared with standard treatment. The financial cost of these benefits depends on assumptions about how long the effects of treatment persist, but, even if benefits decline after five years, each year of healthy life “costs” about $47,000. If the treatment retains its effectiveness over the patient’s entire life, its price would be $28,000 per year of healthy life.
An intervention that adds a year of perfect health at the price of no more than $50,000 would generally be considered cost-effective in the United States.
Instead of tracking individuals over time, the study’s authors constructed a hypothetical sample using data from an earlier SPRINT trial. Using these previous results, the team estimated the risk of death and serious adverse events in 10,000 hypothetical patients who underwent either standard or intensive systolic blood-pressure treatment.
In the first SPRINT trial, published in NEJM in November 2015, more than 9,000 participants were randomly assigned to two groups that received either a systolic blood-pressure target of 120 (intensive blood-pressure treatment group) or a higher target of 140 (standard treatment group). Because the lower target requires more interventions to achieve — including medication, office visits and lab monitoring — it is called “intensive.” The team found significantly lower rates of fatal and nonfatal cardiovascular events, as well as all-causes death, in the group with the lower, intensive blood-pressure target.
Calculating the cost of health care, even when it is already known to extend life, helps health systems allocate scarce resources. Though they may seem synonymous, more intensive treatment and medical benefit do not always go together. For example, studies on intensive glucose management have not found that it reduces mortality; there may be harms associated with lowering blood sugar that researchers hadn’t anticipated.
Innovative practice solutions like this are how the Christiana Care Value Institute improves the experience of health care for patients and providers, said Eric V. Jackson Jr., M.D., MBA, associate director of the Value Institute and director of health care delivery science, who noted that the study will help Christiana Care and other health systems understand the cost savings associated with optimal blood-pressure control.
“These two articles have reset the expectations around blood-pressure treatment,” Dr. Jackson said.
The Value Institute’s linkage of clinical practice and research helps care providers move quickly to implement findings in the real world. In other words, research from an academic medical center such as Christiana Care does not have far to travel before it reaches a patient.
Studies that establish a sound financial rationale for health interventions are especially valuable to managed care organizations eager to reduce costs while maintaining quality.
CareVio, Christiana Care’s unique care coordination program, “will be a major beneficiary of this research,” said Mia Papas, Ph.D., director of clinical research and health outcomes at the Value Institute.
The team’s next step is to predict health outcomes around blood pressure at the patient level, Dr. Zhang said, in order to select those individuals who could benefit most from intensive systolic blood-pressure treatment.
Using health care utilization and quality of life measures, they plan to compare the cost-effectiveness of intensive versus standard blood-pressure treatment. To do that, they’ll develop and validate patient-level cost-effectiveness prediction tools.
Finally, they’ll attempt to create benefit-risk profiles using population-based samples of those most likely to benefit from these goals. The study will be funded by the U.S. National Institutes of Health.
Though the team will focus on blood-pressure treatment next, the model they applied to a hypothetical patient base can be applied to evaluate and compare treatments for diabetes, angina, and other chronic diseases.