Digital Phenotyping and Lifestyle Intervention in Patients With Myasthenia Gravis ( <scp>DIG</scp> ‐ <scp>MG</scp> ): A Randomized Controlled Trial of Feasibility, Adherence, and Effects on Fatigue

INTRODUCTION/AIMS: Physical activity and sleep influence fatigue in myasthenia gravis (MG), and digital health technologies (DHT) enable objective monitoring of these behaviors in daily life. Using this approach, we evaluated whether a lifestyle intervention targeting physical activity or sleep hygiene could reduce fatigue in MG. METHODS: In this three-arm, randomized controlled trial (DIG-MG; NCT05992025), 72 MG patients completed 6 weeks of baseline monitoring with a DHT ring (OURA), followed by 12 weeks of (i) physical activity guidance, (ii) sleep hygiene education, or (iii) observation, and a 6-week follow-up. The primary outcome was the MG Activities of Daily Living (MG-ADL) score 1 week postintervention. Secondary outcomes included Fatigue Severity Scale (FSS) scores; exploratory outcomes were DHT-derived physical activity and sleep parameters. RESULTS: Baseline MG-ADL scores were similar (median: 5.0). Postintervention medians were 4.0 (physical activity), 3.5 (sleep hygiene), and 3.0 (control), with no significant differences (p = 0.073). Clinically meaningful MG-ADL improvement occurred in six, seven, and six participants, respectively. FSS scores showed no group differences (p = 0.992), with clinically relevant improvement in eight participants in each intervention group and five controls. Participants were more physically active than expected: 64.7% exceeded 600 MET-min/week at baseline. DHT adherence was excellent. REM sleep was lower than expected, while deep sleep was preserved. Self-reported data aligned with DHT measurements. DISCUSSION: Digital lifestyle interventions were feasible and well-accepted but did not improve MG-ADL or FSS in this unusually active population. However, DHT-based monitoring may support individualized follow-up, and reduced REM sleep warrants further investigation as a fatigue-related factor.