Design matters in secondary prevention: Individualization and supervised exercise improves the effectiveness of cardiac rehabilitation

Background: Hospital or centre-based cardiac rehabilitation (CR) can lengthen and improve life. However, most existing trials do not examine the effects of design characteristics. To examine the effects of these characteristics, this study compared an individualized cardiac rehabilitation programme to a standardized programme and examined what factors contributed most to programme effects. Design: A prospective cohort analysis was done comparing patients using an individualized centre-based cardiac rehabilitation programme (ICR) in a mixed urban-rural region of the west of Scotland, to a standardized cardiac rehabilitation programme (SCR) provided at the same site three years previously. Both inter- and intra-programme differences in outcomes were explored. Results: More patients were referred to ICR than SCR (749 versus 414 patients, p=0.002) and the proportion of patients who subsequently attended was around 30% higher (p<0.0001) although the overall rate of referral to ICR was lower (70% versus 62%, p=0.002). ICR was associated with a reduction in hospital admission compared to SCR (HR: 0.664: 95% confidence interval (CI) 0.554 to 0.797). ICR patients also had significantly shorter hospitalizations (mean: 8.02 days versus 5.84 days, p<0.05). ICR patients who attended at least 75% of the exercise sessions were significantly less likely to be hospitalized than individuals who partially attended (HR 2.39, 95% CI: 1.659 to 3.488) or did not participate in exercise sessions (HR 2.16, 95% CI: 1.482 to 3.143). Conclusions: Individualized content and supervised exercise components are key design characteristics for improving outcomes from centre-based CR in clinically representative populations.