Fidelity of Delivery in a Multisite Randomized Clinical Trial of Intervention Efficacy for Infants With Unilateral Cerebral Palsy.

Purpose: To investigate the reliability of a measure of fidelity of therapist delivery, quantify fidelity of delivery, and determine factors impacting fidelity in the Rehabilitation EArly for Congenital Hemiplegia (REACH) clinical trial.

Methods: Ninety-five infants (aged 3-9 months) with unilateral cerebral palsy participated in the REACH clinical trial. The Therapist Fidelity Checklist (TFC) evaluated key intervention components. Video-recorded intervention sessions were scored using the TFC.

Results: Inter- and intrarater reliability was percentage agreement 77% to 100%. Fidelity of delivery was high for 88.9% of sessions and moderate for 11.1% of sessions. Sessions with moderate scores included infants receiving infant-friendly bimanual therapy and occurred at the intervention midpoint or later. No significant relationships were found for TFC scores and infant age, manual ability, or parent engagement.

Conclusions: Fidelity of delivery was high for the REACH trial in most intervention sessions. Standardized therapist training with intervention manuals and monthly peer-to-peer support likely contributed to these results.