An implementation evaluation of the physical activity counseling for in-patients with major depressive disorder (PACINPAT) intervention: a randomized controlled trial

BACKGROUND: The physical activity counseling for in-patients with major depression (PACINPAT) randomized controlled trial was launched to tackle physical inactivity for in-patients with major depressive disorder. Evidence shows that despite potential treatment effects, physical inactivity is prevalent in this population. To contribute to the assessment of how this in-person and remote, theory-based, individually tailored intervention was designed, received and effected behavior, the aim of this study was to evaluate its implementation. METHODS: This implementation evaluation was conducted within a multi-center randomized controlled trial according to the Process Evaluation Framework by the Medical Research Council including the analysis of reach, dose, fidelity and adaptation. Data were collected from the implementers and the participants randomized to the intervention group of the trial. RESULTS: The study sample comprised 95 physically inactive in-patients (mean age: 42 years, 53% women) with diagnosed major depressive disorder. The intervention reached the intended population (N = 95 in-patients enrolled in the study). The intervention dose varied between early dropouts (counseling sessions, M = 1.67) and study completers with some participants receiving a low dose (counseling sessions, M = 10.05) and high dose (counseling sessions, M = 25.37). Differences in the attendance groups were recognizable in the first two counseling sessions (duration of counseling session about 45 min in early dropouts versus 60 min for study completers). Fidelity of the in-person counseling content was partly achieved and adapted, whereas that of the remote counseling content was well achieved. Participants (86% at follow up) reported satisfaction with the implementers of the intervention. Adaptations were made to content, delivery mode and dose. CONCLUSION: The PACINPAT trial was implemented in the intended population, in varying doses and with adaptations made to in-person counseling content and remote counseling dose. These findings are key to understanding outcome analyses within the PACINPAT trial, further developing interventions and contributing to implementation research among in-patients with depressive disorders. TRIAL REGISTRATION: ISRCTN, ISRCTN10469580, registered on 3(rd) September 2018.