Withings Hypertension Notification Retrospective Study (HTNF)

Withings

Status: Active, not recruiting

Conditions: Hypertension

Treatments: Device: Withings Blood Pressure Monitor (reference); Device: Withings Hypertension Notification Feature (HTNF)

Study type: Observational

Funder types: Industry

Identifiers

NCT07631715

HTNF

Details and patient eligibility

About

This retrospective, non-interventional clinical investigation evaluates the diagnostic performance of the Withings Hypertension Notification Feature (HTNF), a software-only medical device (SaMD) that analyzes demographic, anthropometric, and physiological parameters collected by Withings connected smart scales to identify patterns suggestive of hypertension. Ground-truth blood pressure measurements are obtained concurrently from Withings connected blood pressure monitors. The study tests whether the Withings HTNF achieves diagnostic performance substantially equivalent to the FDA-authorized predicate device (Apple Watch HTNF, K250507) for the purpose of 510(k) clearance.

Full description

Hypertension affects approximately 1.4 billion adults worldwide and is the leading modifiable risk factor for cardiovascular disease. In September 2025, the FDA granted 510(k) authorization (K250507) to Apple Inc. for a Hypertension Notification Feature on Apple Watch, establishing the first regulatory precedent for consumer wearable-based hypertension screening.

The Withings Hypertension Notification Feature (HTNF) is a software-only medical device (Software as a Medical Device, SaMD) that analyzes demographic, anthropometric, and physiological parameter data opportunistically collected by Withings connected smart scales to identify patterns suggestive of hypertension and provide a notification to the user. Ground-truth hypertension status is defined at the user-week level as a weekly average systolic blood pressure (SBP) >= 130 mmHg or diastolic blood pressure (DBP) >= 80 mmHg (2017 ACC/AHA guideline), based on a minimum of 7 weekly blood pressure measurements from Withings BPM devices.

The co-primary endpoints are the stage-adjusted sensitivity and stage-adjusted specificity of the Withings HTNF algorithm on a held-out validation set, evaluated via a conjunctive intersection-union test (IUT) at one-sided alpha = 0.025. Stage adjustment is performed via Direct Standardization to the predicate's stage distribution. Confidence intervals are derived using BCa bootstrap resampling with at least 10,000 replicates.

Secondary endpoints include stage-specific Se/Sp, PPV/NPV, AUC-ROC, subgroup performance (age, sex, BMI, race/ethnicity, device model, prior HTN diagnosis, antihypertensive medication), and time-to-first-false-positive analyses. For the US cohort, race, ethnicity, diagnosis, and medication history are obtained via linkage to the HealthVerity claims database.

Data were collected retrospectively between 2019 and 2026 from consumer users of commercially available Withings smart scales who received an information letter and did not opt out. No prospective measurements or interventions are performed.

Enrollment: 2,500 estimated patients

Sex: All

Ages: 18 to 100 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Users of commercially purchased, consumer-grade Withings smart scales (models Body Cardio, Body Comp, Body Scan) in a standard home environment
• Concurrent ground-truth blood pressure data collected via Withings connected blood pressure monitors (BPM, BPM+, BPM Connect, or BPM Core)
• At least 7 blood pressure measurements within a given week to establish reliable weekly hypertension status classification
• Age >= 18 years (all regions) or >= 22 years (United States), consistent with the predicate device age requirement
• Receipt of the study information letter without exercising the right to opt out (for applicable regulatory jurisdictions)

Exclusion criteria

• Users lacking valid weekly average systolic and diastolic blood pressure measurements (missing ground truth)
• Users with physiological measurements falling outside plausible clinical ranges (BMI < 10 or > 100 kg/m2, age < 18/22 or > 100 years)
• Users who exercised their right to opt out of the retrospective study
• Users without an individual Withings account (shared accounts are excluded to prevent data contamination)

Trial design

2,500 participants in 1 patient group

Withings Smart Scale Users

Description:

Retrospective cohort of adult consumer users of Withings connected smart scales (Body Cardio, Body Scan, Body Comp) with concurrent Withings blood pressure monitor measurements between 2019 and 2026. The held-out validation subset (\~2,500 users) is drawn from the HealthVerity-linked US cohort to support stage-adjusted Sensitivity and Specificity primary endpoints and subgroup analyses.

Treatment:

Device: Withings Hypertension Notification Feature (HTNF)

Device: Withings Blood Pressure Monitor (reference)