Background: The Copenhagen Outpatient ProgrammE-Implantable Cardioverter Defibrillator trial was a randomized clinical trial that compared a complex rehabilitation intervention including exercise training and psychoeducational interventions with usual care. A significant difference between rehabilitation and usual care was found in physical capacity and general and mental health. However, the clinical effect sizes of these findings were not investigated, and the findings from the quantitative and qualitative analyses were not triangulated to address the issue of whether the qualitative results could help explain the quantitative results and bring forward additional information.
Objectives: The objectives are to (a) determine the clinical effect sizes of the primary outcomes and (b) triangulate the quantitative and qualitative findings.
Methods: A total of 196 patients with first-time implantable cardioverter defibrillator implantation were randomized (1:1) to comprehensive cardiac rehabilitation (12 weeks of exercise training and 1 year of psychoeducational follow-up) versus treatment as usual. Two primary outcomes, perceived health (Short Form-36) and peak oxygen uptake, were used. Cohen d was calculated. Qualitative interviews were conducted with 10 patients representing the rehabilitation group. Triangulation was carried out by integrating the findings from the quantitative and qualitative results in light of each other.
Results: Clinically meaningful effects were found between groups in peak oxygen uptake, general health, and mental health in favor of the rehabilitation group. Within groups, we found medium/high effect sizes on the mental component score in the rehabilitation group over time and only a small effect in the usual care group. The mechanisms of these effects were further explained by the qualitative findings. Patients with better physical health learned how to interpret body signals and adjust exercise behavior and experienced increased physical capacity. Those with better mental health received support that assisted them to cope with the possibility of shock and death and regain trust in their bodies.
Conclusion: The program has a clinical effect and is perceived as beneficial through supportive coping.