A mixed-methods process evaluation of the ‘Walk with Me’ peer-led walking intervention to increase physical activity in inactive older adults

Abstract

Purpose: Process evaluations of complex interventions are crucial to looking beyond outcomes by describing implementation, mechanisms of impact and context. The overarching aim of the thesis was to conduct a process evaluation of the ‘Walk with Me’ (WWM) peer-led walking intervention for inactive older adults in accordance with the Medical Research Council (MRC) process evaluation guidance.

Methods: A systematic review of process evaluations in physical activity interventions for older adults showed that process evaluations lack rigour in methods and reporting when assessed against MRC guidance. The process evaluation of WWM sought to address this gap by applying a mixed methods approach. This comprised of three distinct studies which included the collection and analysis of: 10 focus groups with mentors (n=16) and participants (n=30); 23 audio recorded meetings between mentors (n=10) and participants (n=19); 32 participant diaries, and 8 mentor diaries. Findings from each study were compared to test the assumptions of the WWM intervention logic model.

Results: The most frequently delivered, received and enacted BCTs were social support, goal setting, self-monitoring and problem solving, and the application of these strategies was effective at increasing walking among participants. The mentor played a facilitating role in the delivery of key intervention components and behaviour change techniques. Qualitative analyses highlighted enjoyment derived from walking with others and in stimulating physical environments as key motivators for engagement. Key contextual influences of heavy rain, time of year, caring responsibilities and dog ownership were identified.

Conclusions: Findings suggest that the synergistic effect of walking with others and in nature were crucial to achieving positive outcomes in the WWM intervention and hold promise as mechanisms for the maintenance of activity. The causal mechanisms and contextual influences identified in this process evaluation should prove valuable to informing future peer-led walking intervention design.

Thesis is embargoed until 31 May 2027.

Date of Award	May 2025
Original language	English
Supervisor	Liz Simpson (Supervisor), Marie Murphy (Supervisor) & Mark Tully (Supervisor)