Imagine there’s a new pill on the market. It promises you a one in 200 chance of avoiding a heart attack, stroke, heart failure or death over the next year — if you take it religiously.
It also promises a one in 60 chance of landing you in the hospital for some serious complication: Maybe you passed out. Maybe the pill affected your kidney function. Maybe you developed a severe electrolyte imbalance.
Would you take it? How would you decide?
This question is confronting some patients with hypertension as well as their health-care providers who, like me, help manage their blood pressure. The “pill” is not a pill per se, but a treatment strategy.
In November of 2015, researchers published results of a large NIH-sponsored trial known as SPRINT, which compared two systolic blood pressure treatment targets for hypertensive adults: a higher, conventional target of 140 mm mercury compared to a more stringent target of 120. Participants in the trial were older, did not have diabetes, and were generally at high risk of developing cardiovascular disease. They were prescribed commonly used blood pressure medications, which were carefully adjusted by investigators to achieve target blood pressures.
The trial demonstrated a large relative benefit: Those in the lower target group had about a 25 percent reduction in the rate of cardiovascular disease or death. The absolute benefit, though, was small, with only about one in 200 patients avoiding cardiovascular disease or death as a result of treatment. The trial also showed that complications in the lower target group were relatively common.
As a physician, I’d love to be able to tell the patient in my exam room whether she will be the lucky one out of 200 who will benefit. That dream is still a few years off. I can, though, answer a related question. If I treat a large group of patients, on the whole, will my patients benefit? Or will the harms of treatment outweigh the benefits? And if the treatment is overall beneficial, what investment will we need to achieve this gain in health?
To answer this question, I teamed up with a group of researchers at Stanford. Our team included experts in cost-effectiveness analysis as well as students developing clinical and analytic expertise in this area. We used data from SPRINT along with other published sources to project the expected benefits, harms and costs from targeting a lower or higher blood pressure over the course of a lifetime.
Results of our study were published this week in JAMA Cardiology. We found that targeting a lower blood pressure results in a substantial net benefit, even after accounting for harms from common, serious adverse events. This net benefit, though, doesn’t come free: An investment of about $23,777 is required for every year of life gained from this strategy.
Is $23,777 “worth it?” It’s a hard question to answer and it depends, in part, on who is paying. But in the spectrum of medical interventions that we routinely use here in the United States, this would be considered a good deal, a bargain even.
So should we go all in? Should we push stringent blood pressure targets for everyone?
No. There are a number of other considerations. SPRINT answered a specific question about hypertension treatment in a specific group of patients. Whether other groups of patients, like those at lower risk of cardiovascular disease, would benefit is unclear. There were also methodological quirks that have left the trial open to criticism.
But if we believe that the findings from SPRINT are generally correct, a lower blood pressure target seems to provide significant health gains for a reasonable cost in patients who are at high risk of developing cardiovascular disease.
Ilana B. Richman, MD, is a VA Health Services Research and Development Fellow at Stanford Health Policy.