Development and implementation of measurement-based care for children and youth with complex mental and neurodevelopmental needs: early experiences from Ontario's Extensive Needs Service.

Introduction: Measurement-based care (MBC) is a structured approach to collecting patient-reported outcome measures (PROMs) to inform clinical care. While MBC is routinely used in mental health settings, its application in neurodevelopmental populations-particularly those with co-occurring physical and mental health conditions-remains limited. Methods: MBC was implemented across three Ontario hospital Extensive Needs Service (ENS) sites in Toronto, Hamilton, and Ottawa. Selection of PROMs was informed by a focused literature review and consultation with clinicians, researchers, and family advisors. A logic model was developed to guide evaluation and link measures to anticipated outcomes. Clinicians received training and support to integrate PROMs into clinical workflows. Data were collected at baseline and at regular intervals. Results: Between April 2023 and April 2025, 381 participants entered the ENS program, and 36 were discharged. Their duration of participation ranged from 3 to 20 months. Each site engaged clinical staff in PROM completion. Completion rates for measures were higher at baseline and declined over time. Shorter PROMs showed higher completion rates compared to longer ones. Discussion: This novel implementation of MBC provides important insights for MBC in pediatric populations with high complexity. Early and ongoing engagement of both clinicians and families is important to success, which is also closely tied to the degree to which MBC is integrated into care processes. MBC remains necessary to guide clinical care and treatment planning for children with complex, intersecting needs. It is also helpful when evaluating new programs and generating foundational evidence on the effectiveness of therapies for this population.