Aim Cardiac rehabilitation (CR) under-attendance presents a global challenge. The Queensland Cardiac Outcomes Registry is a comprehensive clinical registry that routinely collects point-of-care CR data. We aimed to determine whether demographic, clinical, psychosocial, and behavioural characteristics of the population vary between those who (i) declined, (ii) commenced but did not complete, and (iii) completed CR.

Methods The cohort comprised 33,055 patients referred to one of 56 Queensland CR services extracted from the Queensland Cardiac Outcomes Registry (2020–2022). Bivariate and multivariable logistic regression analyses were used to identify factors associated with CR non-attendance and non-completion.

Results Over the study period, 12,152 patients (37%) declined CR, 11,621 (35%) initiated but did not complete CR, and 9,282 (28%) completed CR. Significant predictors of CR non-attendance were aged ≥75 years (adjusted odds ratio [aOR] 1.51; 95% confidence interval [CI] 1.42–1.61), Indigenous status (aOR 1.65; 95% CI 1.50–1.81), living regionally (aOR 1.76; 95% CI 1.65–1.87) or remotely (aOR 2.33; 95% CI 1.92–2.82), and having arrhythmia (aOR 2.38; 95% CI 2.07–2.73), heart failure (aOR 1.54; 95% CI 1.37–1.74), non-ST-elevation myocardial infarction (aOR 1.30; 95% CI 1.21–1.40) or unstable angina (aOR 1.24; 95% CI 1.1.13–1.37). Significant predictors of CR non-completion were age <55 years (aOR 1.55; 95% CI 1.37–1.75), Indigenous status (aOR 1.60; 95% CI 1.29–1.98), living regionally (aOR 1.29; 95% CI 1.12–1.48), obesity (aOR 1.14; 95% CI 1.01–1.28), being a current (aOR 1.97; 95% CI 1.70–2.27) or former smoker (aOR:1.22, 95% CI 1.11–1.33) and having low social support (aOR 1.58; 95% CI 1.24–2.02).

Conclusion As one of the largest studies of CR participation to date, these findings can now be applied to develop targeted, co-designed initiatives to enhance CR participation, especially among First Nations populations, smokers, those with limited social support, people living regionally/remotely, patients with arrhythmia and heart failure, and those in varying age groups.