Since 2015, hypertension care has been contentious because of a single study: SPRINT (Systolic Blood Pressure Intervention Trial).¹ This study, sponsored by the National Institutes of Health, was designed to answer a question debated for more than half a century: Is treatment of mild hypertension with medications warranted and, if so, to what blood pressure targets?² A 2014 review of mild hypertension that I coauthored found little, if any, benefit to treatment.³ Therefore, SPRINT's results surprised myself and others in primary care, as did differing specialty interpretations about how—or whether—these results should influence hypertension management.

SPRINT enrolled 9,361 patients between 2010 and 2013, with a maximum planned follow-up of six years. Participants were required to have an increased risk of cardiovascular events but notably could not have a history of stroke, diabetes mellitus, symptomatic heart failure within the past six months, or a left ventricular ejection fraction less than 35%. Participants were also excluded for arm circumference being too large or too small and the presence of any factors likely to limit adherence to interventions. After enrollment, participants were randomized to a systolic blood pressure target of less than 140 mm Hg (standard treatment) or less than 120 mm Hg (intensive treatment).

The study was abruptly halted in 2015 because an interim analysis suggested “potentially lifesaving information.” ⁴ Two months later, the authors published the number needed to treat to prevent a primary outcome event (61), death from any cause (90), and death from cardiovascular causes (172) during the median 3.26 years of the trial.¹ The intervention group experienced 3.5 fewer deaths per 1,000 people per year compared to the control group.⁵

The American College of Cardiology went all in on SPRINT in 2017, establishing new definitions for hypertension and “normal” blood pressure levels, which recategorized nearly one-half of adults in the United States as hypertensive.^6–9 However, the American Academy of Family Physicians and the American College of Physicians, relying on a broader meta-analysis, instead recommended a systolic blood pressure goal of 150 mm Hg for patients older than 60 years.¹⁰ The European Society of Cardiology also viewed SPRINT's findings with skepticism and did not incorporate them into the organization's recommendations.¹¹ By 2018, international guidelines were significantly discordant.¹²

During the same period, researchers took a closer look at SPRINT's methodology. In SPRINT, blood pressure was measured using ideal techniques that are unlikely to be replicated in standard practice.^13–15 As described by a SPRINT principal investigator, the protocol included “. . . sitting quietly with your feet on the floor for 5 minutes, no smoking, no drinking coffee, no talking, no disturbance in the room. . . . So if you [in primary care] try to push those clinic pressures down to 120, you may get into trouble.”¹⁶

In July 2022, the American Academy of Family Physicians further refined its recommendations, returning to the well-supported goal of 140/90 mm Hg for most clinical situations.¹⁷ Later that year, we finally learned what happened when SPRINT participants returned to routine practice: blood pressure in the intensive treatment group increased, resuming parity with the standard treatment group.^18,19 Authors of the companion editorial speculated that SPRINT's “vigorous” strategies, including at least six visits each year for participants in the intensive treatment group, may not be feasible for busy primary care practices.¹⁹ Also, the visit-to-visit variability in office-measured blood pressure in the real world makes it unlikely that SPRINT's transient benefits can be achieved safely and effectively.²⁰

Recognizing that hypertension is the most important risk factor for disability and death,²¹ what can we do? Increasing staff could allow us to regularly perform the 19 steps of accurate blood pressure measurement described in the American College of Cardiology guideline,⁶ but the health care workforce is instead at a historic deficit.²² As for the overall time needed, colleagues in Norway have crunched the numbers: they would first need additional physicians, and then each one could provide only hypertension care.^23,24 What health benefits would be achieved? For treated patients with mild hypertension, number needed to treat CIs for cardiovascular events over five years range from 55 to 1,188, translating to a personal probability benefit of 0.08% (1 in 1,188) to 1.8% (1 in 55) for any given patient.^25,26

Shared decision-making to describe these unlikely benefits would be challenging at best. SPRINT's influence on the diagnosis and management of hypertension, particularly mild hypertension, has caused disagreement and confusion. There are a number of lessons and cautions to consider (Table 1).^{10,17,27–31} The most profound concern is that primary care efforts are not translating into epidemiologic improvements. Despite our efforts to treat hypertension and diabetes, the prevalence of these conditions continues to rise, and they are becoming less controlled.^32,33 We are increasingly asked to emphasize lifestyle measures, yet these recommendations are rarely effective.^34,35 Does working harder and longer in primary care with individual patients address population-level prevention in a useful way? Are we right for this job?

In 2008, toward the end of her career, Barbara Starfield—a champion of our work—expressed the same concern: “In its focus primarily on professionally defined disease entities, the practice of medicine (and particularly the practice of ‘prevention’) is moving increasingly further from its roots in the care of patients—true ‘patient-centered care.’ ”³⁶

The four fundamental aspects of primary care Starfield identified are first-contact; long-term, person-focused (not disease-focused); comprehensive; and coordinated. She noted that these aspects concern true patient-centered care, not prevention.³⁷ Prevention takes a lot of time,²³ and patients are increasingly unable to access our essential work of “resolving undifferentiated illness and providing balanced care for complex medical conditions.”^38,39 SPRINT is a cautionary tale of how harm can occur, directly and through opportunity costs, in the pursuit of prevention. Let's please learn from it.