Mediating Effects of the 'eCoFit' Physical Activity Intervention for Adults at Risk of, or Diagnosed with, Type 2 Diabetes.

BACKGROUND: The study aim was to examine the mechanisms of physical activity behaviour change in the multi-component eCoFit randomised controlled trial (RCT) among adults diagnosed with, or at risk of, T2D. METHOD: The RCT included two phases: phase 1 (weeks 1-10) integrated group sessions (outdoor physical activity and cognitive mentoring) and the use of the eCoFit smartphone application (app), and phase 2 (weeks 11-20), which included the use of the eCoFit smartphone application only. Participants (n = 84) were assessed at baseline and 10 and 20 weeks from baseline. Physical activity was assessed using pedometers, and the following mediators were tested: action self-efficacy, barrier self-efficacy, recovery self-efficacy, implementation intentions, intention to have regular physical activity, outcome expectations, risk perception and implicit associations related to physical activity. The PROCESS INDIRECT Macro was used to perform mediation analyses. RESULTS: Significant mediation pathways were found for implementation intention measured at 10 weeks, AB (95% CI = 486.04 [128.19, 1073.42]). No significant pathways were found for the other social-cognitive and implicit attitudinal mediators. CONCLUSION: Increased daily steps among the intervention participants were explained by increased implementation intentions. The eCoFit study successfully operationalised implementation intentions in the smartphone app designed to promote outdoor physical activity. TRIAL REGISTRATION: The trial was approved by a University Human Research Committee and is registered with the Australian New Zealand Clinical Trial Registry (ACTRN12615000990527).