Quality of secondary prevention in centre-based cardiac rehabilitation: predictors and between-center variation

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Slovenian Research Agency Ministry of Health, Republic of Slovenia. Background Cardiac rehabilitation (CR) is a complex intervention, providing supervised exercise training, risk factor control, and secondary prevention. Centre-based outpatient CR provides the necessary structure to accomodate the delivery of several preventive interventions, but the quality of secondary prevention may vary. The present study sought to assess the impact of CR on the improvement and between-center variation of the quality of secondary prevention. Methods Data were extracted from the Slovenian National CR Registry for patients who completed CR between 2017 and 2020. A composite quality score (CQS) was calculated adjudicating one point for each of the following: non-smoking status, body mass index <25 kg/m2, systolic blood pressure <130 mmHg, low-density lipoprotein (LDL) cholesterol <1.4 mmol/L, antiplatelet therapy, and high-potency statin/combined lipid-lowering therapy. Predictors of CQS improvement were assessed using mixed-effects ordinal logistic regression model acknowledging the hierarchical nesting of patients within centres. Results A total of 1,952 patients from 5 centres were included (mean age 59.4±10.8 years; 22% women). Mean CQS improved from 3.16±1.11 to 3.53±1.21 (p<0.001), with CR associated with an OR 1.72 (95% confidence interval [CI] 1.49-2.00) for CQS improvement (Figure). Improvement of CQS was also positively associated with increasing number of sessions >12 (e.g., OR 6.06 [3.29-11.14] for 12-24 sessions) and total number of co-morbidities (OR 1.40 [95%CI 1.33-1.48]), and negatively associated with male sex (OR 0.78 [95%CI 0.65-0.92]), high cardiac risk (OR 0.83 [95%CI 0.68-0.99]), age >60 years (e.g., OR 0.62 [95% CI 0.41-0,94] for age group 60-69 years), and referral diagnosis other than STEMI (e.g., OR 0,56 [95%CI 0.39-0,72] for non-infarction coronary artery disease). Random-effects partitioning attributed 68.8% of variance to patient-level factors and 19.8% to between-center variability. Conclusions Centre-based CR is associated with improved quality of secondary prevention; factors affecting quality improvement range from patient-level (e.g., age and sex) to mode of provision (e.g., number of sessions). Up to one fifth of the variation, however, can be attributed to between-center variationm.