I-WEAR: Evaluating Wearables and Health Summaries in ICU Survivors

I-WEAR is a single-center, non-invasive, randomized feasibility study conducted at the Medical University of Vienna in collaboration with the Ludwig Boltzmann Institute for Digital Health and Patient Safety. The study targets ICU survivors aged 18-65 years with prior ICU stays of ≥48 hours and comorbid diabetes mellitus and/or cardiovascular disease. The goal is to evaluate the feasibility and usability of wearable technologies and digital health reporting to enhance longitudinal care after ICU discharge.

Participants (n=60) are randomized into three groups:

Control group: Standard ICU follow-up care Intervention group 1: Wearables and app (smartwatch, scale, blood pressure monitor) Intervention group 2: Same wearables plus automated bi-weekly health summaries and optional health consultations via Webex Wearable devices include the Garmin Vivosmart 5 (tracking HRV, sleep, stress, and activity), the Garmin Index S2 Smart Scale, and the Garmin Index BPM blood pressure monitor. Data is aggregated via the Fitrockr application and stored in an ISO/IEC 27001-certified cloud environment in compliance with the EU General Data Protection Regulation (GDPR). Participants retain full control over data sharing, and pseudonymized data will be used for research purposes only.

The primary outcomes are feasibility (recruitment, retention, device adherence), and usability (System Usability Scale, qualitative interviews). Secondary outcomes include health-related quality of life measured via SF-36 at enrollment, mid-study (month 3), and study completion (month 6). Descriptive statistics and visualizations will summarize adherence and change trajectories. The study follows CONSORT 2010 guidelines for feasibility studies and includes a decision framework to inform whether to proceed with a definitive trial.

Inclusion criteria

• Age 18-65 years at the time of ICU admission
• ICU stay of at least 48 hours
• ICU discharge within the last 2 years
• Comorbidity of diabetes mellitus and/or chronic heart failure/coronary artery disease
• Written informed consent
• Access to a home internet connection and smartphone with internet and Bluetooth

Exclusion criteria

• Presence of a legal guardian
• No smartphone or internet access
• No cardiovascular disease/event and/or diabetes
• Implanted pacemaker or defibrillator
• Allergies to materials in the wearable devices
• Transfer from an ICU outside the Medical University of Vienna
• Homelessness
• Residence outside of Austria