Apple Watch Hypertension Notifications May Give False Reassurance, With Adam Bress, PharmD, MS

Although the Apple Watch’s hypertension notification feature can successfully identify adults with undiagnosed hypertension, recent data highlights its capacity for misclassification.1

The notification feature, which uses photoplethysmography signals to inform users of possible hypertension without a blood pressure cuff, was cleared by the US Food and Drug Administration (FDA) in September 2025. A subsequent validation study comparing the feature to home blood pressure monitoring over 30 days saw 41.2% of patients with undiagnosed hypertension receive an alert versus 58.8% who did not. Among those without hypertension, 92.3% did not receive an alert, while 7.7% received an inaccurate alert.2

“The trustworthiness of a positive test is higher in groups that have a higher prevalence of undiagnosed hypertension,” Adam Bress, PharmD, MS, professor of the department of population health sciences at the University of Utah School of Medicine and director of the Integrating Medicine & Policy to Achieve Healthcare Transformation (IMPACT HSR) program, told HCPLive in an exclusive interview. “The opposite is true with the trustworthiness of a negative test. The risk there is the idea of being falsely reassured that you don’t have hypertension.”

The current study, conducted by Bress and colleagues, incorporated data from the National Health and Nutrition Examination Survey (NHANES) 2017-2020. Patient eligibility was determined based on the intended use population: patients were included if they were non-pregnant, aged ≥22 years, unaware of having hypertension, and not actively taking antihypertensive medication.1

Prevalence of undiagnosed hypertension was estimated in the overall population and select subgroups. Bress and colleagues applied test performance metrics to estimate the percentage of true-positive, false-negative, true-negative, and false-positive results, as well as positive and negative likelihood ratios, positive and negative predictive values, and posttest probabilities.1

A total of 3983 participants were enrolled in the study, representing 127 million US adults. With the estimated prevalence of hypertension in the overall population, the positive predictive value was 69.1% (95% CI, 63.3-74.9%), while the negative predictive value was 79% (95% CI, 76.6-81.3%).1

Analysis was also conducted across subgroups – for example, alerts in patients <30 years increased the probability of hypertension from 0.14 (95% CI, 0.11-0.17) to 0.47 (95% CI, 0.39-0.56), while the absence of an alert lowered the probability to 0.1 (95% CI, 0.07-0.12). However, among patients ≥60 years, an alert raises the probability from 0.45 (95% CI, 0.39-0.5) to 0.81 (95% CI, 0.76-0.86), and the absence thereof lowers it to 0.34 (95% CI, 0.29-0.39).1

Bress and colleagues emphasize the Apple Watch’s explicit statement that the notification feature is not intended to diagnose hypertension – instead, it is designed to prompt users to seek clinical evaluation. However, false reassurance may mislead or discourage individuals from undergoing appropriate screening, ultimately resulting in missed opportunities for early detection and treatment. If future cuffless devices are to contribute to hypertension detection, Bress and colleagues state that rigorous validation and thoughtful integration into population screening will be needed.1

“Clinical inertia is one of the leading causes of why blood pressure control rates are not as good as they could be,” Bress said. “The Apple Watch hypertension notification feature is only designed for people without a diagnosis of hypertension, so it’s not intended or designed for treatment and monitoring of people on antihypertensive medications. However, tools like wearables or home blood pressure monitors to help reduce clinical inertia are very important and are currently under study to hopefully add to the clinician’s toolkit.”

Editor’s Note: Bress reports disclosures with the National Institute on Aging, the National Heart, Lung, and Blood Institute, and Alnylam.

References

1. Cohen JB, Addo DK, Jacobs JA, et al. Impact of a smartwatch hypertension notification feature for Population Screening. JAMA. Published online February 9, 2026. doi:10.1001/jama.2025.26925

2. Browning SC, Assistant Director, Division of Cardiac Electrophysiology, US Food and Drug Administration, to Bonnie Wu, Apple Inc, September 12, 2025, Summary for Apple Hypertension Notification Feature (K250507). Accessed September 15, 2025. https://www.accessdata.fda.gov/cdrh_docs/pdf25/K250507.pdf