Implementation Fidelity in Early Intervention for Eating Disorders-A Multisite Pilot Study.

First Episode Rapid Early Intervention for Eating Disorders (FREED) is an early intervention service model and care pathway for young people aged 16-25 with a recent-onset eating disorder. This multi-site study aimed to evaluate the feasibility of a newly developed implementation fidelity tool and observe patterns of fidelity to FREED. Six eating disorder services across England took part in an assessment. Data were collected from 242 patient referrals between January and June 2025 and via semi-structured interviews with FREED staff. Total fidelity scores were calculated alongside two component scores (rapid access to the service and early intervention care package), and inter-rater agreement was assessed. The tool was feasible to use across multiple services, time efficient, aligned with existing workflows, and demonstrated high inter-rater agreement. The average fidelity score across services was 72% ('medium fidelity'). The average component scores were 57% for rapid access targets ('not satisfactory') and 77% for early intervention care package ('medium fidelity'). Rapid access target scores were highly variable across services (20-87%), whereas care package scores were more consistent (72-82%). Additional sustained resource augmentation is needed to improve model adherence and facilitate consistent access to high-quality early intervention for eating disorders, including support to meet rapid access targets.