Fidelity, Implementation Determinants, and Patient-Level Outcomes Following Initial Implementation of NAVIGATE in the Early Psychosis Intervention—Spreading Evidence-Based Treatment (EPI-SET) Study

Background and Hypothesis While early psychosis intervention (EPI) services are effective, care delivery is often inconsistent, particularly in recovery-oriented care. We hypothesized that facilitated implementation of NAVIGATE, an evidence-based, standardized model of coordinated specialty care, would increase fidelity to EPI standards and improve patient functioning in real-world settings. Study Design The Early Psychosis Intervention-Spreading Evidence-based Treatment (EPI-SET) study was a non-randomized effectiveness-implementation hybrid type III trial in 6 Ontario EPI programs. We used the First Episode Psychosis Services—Fidelity Scale-Revised (FEPS-FS-R) to measure fidelity to EPI standards at baseline (T0) and 12 months (T1). Scores ranged from 1 to 5, indicating poor (<3.5), fair (3.5-4), and good (≥4.0) adherence. The Heinrichs–Carpenter Quality of Life Scale (QLS) was used to determine change in functioning from baseline to 12 months (which roughly coincided with the T1 fidelity assessment). Implementation determinants were assessed using the Consolidated Framework of Implementation Research. Study Results FEPS-FS-R scores indicated good adherence for 19/29 items at T0 and 17/29 items at T1. Compared to T0, at T1, more psychosocial treatment items and fewer access and continuity items achieved fair or better adherence. Among the 100 participants who completed a baseline assessment, QLS total scores improved significantly (estimated change = 13.6, 95% CI: 9.6-17.7, P < .001) from T0 to T1. Implementation experiences varied across sites, with 4 of 6 organizations reporting overall positive experiences. Conclusions Implementation of NAVIGATE was associated with improved fidelity to psychosocial components of care, with concomitant improvements in patient functioning. These findings can inform widespread implementation of NAVIGATE.