Adherence and Acceptability of Smartphone- and Wearable-Based Digital Phenotyping in Patients With First-Episode Psychosis: Observance et acceptabilité du phénotypage numérique fondé sur les téléphones intelligents et les objets personnels connectés

Objective To examine adherence to smartphone- and wearable-based digital phenotyping in patients with first-episode psychosis (FEP) and explore stakeholder perspectives on its potential application for outcome prediction. Method We conducted a six-day mixed-methods digital phenotyping assessment involving ecological momentary assessment (EMA) via smartphone and passive monitoring using wearable devices. Patients with FEP (aged 12–35) were recruited from the Early Psychosis Intervention Nova Scotia program ( N = 40). The present analysis focuses on adherence, acceptability, and stakeholder perspectives. Active and passive adherence were defined as the proportion of completed EMA surveys and available wearable data, respectively. Exploratory mixed-effects regression analyses were conducted to examine temporal trends and factors associated with adherence. Semi-structured interviews were conducted with 19 patients, six caregivers, and six clinicians, and analyzed thematically. Results Mean active adherence was 71.32% (SD = 28.77). Mean passive adherence was 85.45% (SD = 25.80) for heart rate and accelerometry, and 82.90% (SD = 26.65) for sleep data, respectively. The odds of EMA survey completion declined beginning on Day 3, and passive adherence rate declined beginning on Day 2; however, neither trend remained significant after adjusting for prior adherence. In exploratory analyses, no consistent associations were observed between most demographic or clinical variables and adherence. Higher Social and Occupational Functioning Assessment Scale score was associated with lower odds of EMA survey completion (OR = 0.91, 95% CI: 0.84, 0.98), a finding that should be interpreted cautiously given the small sample. Barriers to adherence were identified by stakeholders, including EMA survey burden, psychological risks, usability and technical challenges, and inaccessibility to digital tools due to school or work restrictions. Conclusion Digital phenotyping appears generally feasible and acceptable in clinically stable FEP patients, but implementation should incorporate safeguards to minimize EMA burden, psychological distress, usability barriers, and ethical risks related to future predictive feedback.