Validation of a Low-Burden, Once-Daily Obsessive-Compulsive Disorder Measure Over 70 Days: Ecological Momentary Assessment Study

Abstract Background Ecological momentary assessments (EMAs) are an increasingly popular tool used to measure real-time symptom burden within mental health care, including for obsessive-compulsive disorder (OCD). However, prior studies in the literature have been limited by brief assessment periods, high participant burden, and heterogeneity in both sampling and symptom assessment methodologies. Objective This study aimed to validate a 12-item EMA questionnaire of OCD symptoms by evaluating its psychometric properties over an extended monitoring period. Methods Adults with OCD (22/41, 53.7%) and demographically matched healthy controls (19/41, 46.3%) completed up to 70 daily smartphone-delivered EMA surveys assessing the frequency and emotional impact of obsessions and compulsions. Participants with OCD also underwent clinician-administered Yale-Brown Obsessive-Compulsive Scale evaluations at weeks 0, 2, and 10. Results Our scale demonstrated high internal consistency (Cronbach α=0.96) and convergent validity, with significant correlation with Yale-Brown Obsessive-Compulsive Scale scores at week 2 (ρ=0.59; P =.004) and week 10 (ρ=0.53; P =.01). Participant retention (89.1%) and questionnaire completion rate (89%) were also higher than those seen in the literature (75.2% and 74.2%, respectively). Conclusions Overall, we provide initial psychometric support for the use of a low-burden EMA tool to capture day-to-day OCD symptom fluctuations over extended periods. Such tools may enhance longitudinal symptom monitoring, improve treatment response tracking, and address limitations inherent in traditional retrospective assessments.