A park-based group mobility program for older adults with difficulty walking outdoors: a quantitative process evaluation of the Getting Older Adults Outdoors (GO-OUT) randomized controlled trial

Background Process evaluations of randomized controlled trials (RCTs) of community exercise programs are important to help explain the results of a trial and provide evidence of the feasibility for community implementation. The objectives of this process evaluation for a multi-centre RCT of outdoor walking interventions for older adults with difficulty walking outdoors, were to determine: 1) implementation fidelity (the extent to which elements of the intervention were delivered as specified in the original protocol) and 2) participant engagement (the receipt of intervention components by the participants) in the Getting Older Adults Outdoors (GO-OUT) trial.Methods GO-OUT participants attended an active 1-day workshop designed to foster safe, outdoor walking skills. After the workshop, 190 people at 4 sites were randomized to an outdoor walk group (OWG) (n = 98) which met 2x/week for 10 weeks, or the weekly reminders (WR) group (n = 92) which received a phone reminder 1x/week for 10 weeks. The OWG had 5 components - warm-up, continuous distance walk, task-oriented walking activities, 2(nd) continuous distance walk, and cool-down. Data on implementation fidelity and participant engagement were gathered during the study through site communications, use of standardized forms, reflective notes of the OWG leaders, and accelerometry and GPS assessment of participants during 2 weeks of the OWG.Results All sites implemented the workshop according to the protocol. Participants were engaged in all 8 activity stations of the workshop. WR were provided to 96% of the participants in the WR intervention group. The 5 components of the OWG sessions were implemented in over 95% of the sessions, as outlined in the protocol. Average attendance in the OWG was not high - 15% of participants did not attend any sessions and 64% of participants in the OWG attended > 50% of the sessions. Evaluations with accelerometry and GPS during week 3 and 9 OWG sessions suggest that participants who attended were engaged and active during the OWG.Conclusions This process evaluation helps explain the main study findings and demonstrates the flexibility required in the protocol for safe and feasible community implementation. Future research could explore the use of additional behaviour change strategies to optimize attendance for community implementation.