Withings HFRN Retrospective Study

Validation of the Withings Heart Function Risk Notification (HFRN)

This is a fully decentralized retrospective, non-interventional study evaluating the diagnostic performance of the Withings Heart Function Risk Notification (HFRN), a software-only medical device (SaMD)

This is a fully decentralized retrospective study.

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)