Improving Cardiac Rehabilitation Utilisation is Essential to Reducing Mortality and Cardiovascular Readmission: A Data Linkage Analysis of Cardiac Rehabilitation Utilisation and Clinical Outcomes of 84,064 Eligible Separations in South Australia

Cardiac rehabilitation (CR) evidence may not translate into practice due to low participation. We aimed to determine CR utilisation and effectiveness in South Australia. This retrospective cohort study used data linkage between CR, hospitals and deaths databases and applied inverse probability weighting and adjusted Cox survival models to assess the association between CR utilisation (no CR received/commenced but not completed/completed) and 12-month all-cause mortality/cardiovascular readmissions. Associations with non-referral and non-completion were assessed by logistic regression. Among 84,064 eligible separations, 31.9% were referred to CR. Of these, 36.8% commenced the program with 77.8% of those commencing completing it. Median time from discharge to referral and from discharge to commencement was 6 (IQR 2-11) days and 40 (IQR 23-79) days, respectively. Female sex (OR 1.77; 95% CI 1.71-1.83; p<0.001) and obesity (OR 1.92; 95% CI 1.52-2.42; p<0.001) were associated with non-referral. Whereas female sex (OR 1.14; 95% CI 1.01-1.29; p<0.032); socioeconomic disadvantage (OR 0.96; 95% CI 0.93-0.98; p<0.001); waiting time (OR 1.06; 95% CI 1.01-1.12; p=0.026) and telehealth (OR 0.25; 95% CI 0.21-0.30; p<0.001) were associated with non-completion. Compared to those not receiving CR, patients who commenced but did not complete (HR 0.81; 95%CI 0.73-0.90; p<0.001) had a lower risk of events. However, those who completed CR showed an even lower risk (HR 0.62; 95%CI 0.58-0.66; p<0.001). CR shows a dose-response effect on mortality/cardiovascular readmissions. Delivery via telehealth and tailoring referral systems and programs to the needs of women, disadvantaged and people with obesity may increase participation.