Withings HFRN Retrospective Study

This is a fully decentralized retrospective study.

• Withings Heart Function Risk Notification (HFRN) (Device): Software-only medical device (SaMD)
• Claims-based heart-failure adjudication (reference standard) (Other): Ground-truth heart-failure case / control status derived from administrative claims by a deterministic, pre-specified rule set.

Primary outcomes

• Sensitivity (Se) of the HFRN algorithm [13 weeks]
• Specificity (Sp) of the HFRN algorithm [13 weeks]

Sex: All, ages: 45 Years to 120 Years, accepts healthy volunteers

Inclusion Criteria:

* Users of commercially purchased, consumer-grade Withings smart scales
* A source of step counts synced into the Withings ecosystem (a Withings activity tracker, a smartphone, or a third-party activity tracker)
* Claims linkage available, enabling heart-failure ground-truth ascertainment
* Age >= 45 years
* At least one 13-week quarter in which at least one of the three quarterly features (mean BMI, standard deviation of body-water percent, 90th-percentile daily steps) can be computed

Exclusion Criteria:

* Users for whom heart-failure status cannot be determined from claims (unknown label; e.g. controls with < 2 years of continuous enrollment)
* Users with no usable measurement after per-reading plausibility screening
* Users without an individual Withings account (shared accounts excluded to prevent data contamination)

• Pierre Escourrou, MD, PhD, Principal investigator, Centre Interdisciplinaire du Sommeil, Paris, France