Predictors of poor exercise self-efficacy improvements after cardiac rehabilitation

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): SOLVE-CHD Australian Government National Health and Medical Research Council (NHMRC) Synergy Grant [GNT1182301] PhD Scholarships Background/Introduction Building confidence to exercise regularly (exercise self-efficacy (ESE)) in the face of constraints and barriers, is a key goal of cardiac rehabilitation (CR) because such self-efficacy beliefs are predictors of sustained exercise behaviours. Therefore, identifying patient subgroups at risk of poor ESE enables tailoring of CR and appropriate targeting of support interventions. Purpose To identify independent predictors of poor ESE and poor improvements in ESE in CR participants. Methods The study used a prospective observational cohort design and recruited patients with coronary heart disease at CR entry across four sites in Metropolitan Sydney, Australia (2019-2020). Data were also compared for traditional in-person and remote-delivered CR during COVID-19 pandemic restrictions. The Exercise Self Efficacy Scale was used to measure ESE at CR entry and completion, and General Linear Models were used for analyses. Results Participants (n=194) had a mean age of 65.94 (SD 10.46) years, with 80.9% males; and 80.0% were married or partnered, with 23.6% from an ethnic minority background. Referral diagnosis included elective percutaneous coronary intervention (PCI) (40.2%), coronary artery bypass surgery (26.3%), and myocardial infarction with or without PCI (33.5%). At CR entry, the mean ESE score was 24.93 (SD 5.99) points, which improved significantly by completion (p=.027). The GLM of ESE change (Adjusted R2=.247) identified that predictors of less change in ESE scores by CR completion included ethnic minorities (β=2.96, p=.003), not having a spouse or an intimate partner (β=-2.42, p=.023), and attending in-person CR (β=1.75, p=.036). Having higher ESE scores at entry was also associated with less ESE change on completion, such that for every point increase in ESE at entry, there was a reduction of .37 points in change (