Exercise-Based Cardiac Rehabilitation in Patients with Coronary Artery Disease : Attendance, Adherence and the Added Value of a Behavioural Medicine Intervention

Abstract: Background: Coronary artery disease (CAD) is the leading global cause of death. After an index event related to CAD, exercise-based cardiac rehabilitation (exCR) is strongly recommended as part of the secondary prevention. Despite the well-established beneficial effects of exCR in patients with CAD, attendance at and adherence to the programme are low, and remain a matter of major concern. One strategy that may increase adherence and rehabilitation outcomes in patients with CAD is to add a behavioural medicine intervention to routine exCR care. The added value of such interventions needs to be further explored. Although several factors associated with non-attendance at exCR appear to be similar between different countries, patterns of attendance may differ due to differences in contextual aspects. The factors that affect attendance at exCR in a Swedish context remain to be explored.Overall aim: To investigate barriers for exCR attendance and to evaluate the added value of a behavioural medicine intervention in physiotherapy on exercise adherence and rehabilitation outcomes in patients with CAD.Methods: The three papers in this thesis are based on two studies of patients with CAD, one registrybased cohort study of 31,297 patients included from the SWEDEHEART registry (Paper I), and one randomised controlled trial of 170 patients included at a Swedish university hospital (Papers II and III). In the first paper, several individual and structural variables were compared for attenders and nonattenders, using multivariable analysis in a logistic regression model. In Papers II and III, patients were randomised 1:1 either to a behavioural medicine intervention in physiotherapy in addition to routine exCR care or to routine exCR care alone for four months. The behaviour change techniques used in the behavioural medicine intervention – specific goal-setting, re-evaluation of the goals, and selfmonitoring and feedback – were based on control theory. Outcome assessment took place at baseline, four and 12 months, and included physical fitness, psychological outcomes and health-related quality of life. Exercise adherence was evaluated at the end of the four-month intervention. An intention-to-treat and a per-protocol analysis were performed.Results: Individual and structural factors associated with non-attendance at exCR in a Swedish context were identified as having a distance greater than 16 km to the hospital, belonging to a county hospital, having a higher burden of comorbidities, being male, and being retired. Exercise adherence was higher for patients who received the behavioural medicine intervention in physiotherapy together with routine exCR (31%) than it was for those who received routine exCR care alone (19%). Rehabilitation outcomes did not differ significantly between the two groups, either between baseline and four months or between four and 12 months. Both groups improved significantly in all measures of physical fitness, and in several measures of health-related quality of life and anxiety at the four-month follow-up. Sufficient enablement remained for patients in both groups at the 12-months follow-up.Conclusions: Distance to the hospital was the strongest predictor for non-attendance at exCR in a Swedish context. The individual factors associated with non-attendance at exCR identified in this thesis confirm previous results, with the exception that female gender was associated with a higher attendance at exCR. The results of this thesis confirm what others have pointed out: it is challenging to achieve behavioural change in patients with the aim to improve rehabilitation outcomes. Even though adherence was higher when a behavioural medicine intervention was added, it was low in both groups. The current behavioural medicine intervention in physiotherapy did not give any improvements over routine exCR care alone in physical fitness, psychological outcomes or health-related quality of life. As such, there is still room for further development and evaluation of behavioural medicine interventions within the context of exCR. A greater tailoring of these interventions to individual needs in a broader population of patients with CAD is suggested.