The effects of usual Care in Psychosocial Intervention Trials of patients with coronary artery disease: a systematic review.

Background: Many intervention studies of coronary artery disease (CAD) have found health benefits for patients in the "treatment as usual" (TAU) group like in the specific psychotherapy group. In this pilot study, we wanted to examine and discuss the role and reasons for TAU effects.

Methods: By means of a systematic review, we examined the control conditions from psychotherapeutic RCTs with CAD patients related to depressive symptoms, mortality and recurrence rate of events. The review question was limited to factors influencing the TAU effectiveness in such psychotherapeutic outcome studies.

Results: We found a decrease in depressive symptoms in TAU patients (mean ES: 0.65) and very differing mortality and recurrence rates of events. The effects were dependant on the year the study was published (1986-2016), the follow-up time of the study (0.25-7.8 years) and the treatment arms. A small dose of additional counselling, medical attention, and teaching of therapeutic techniques with clinical competence may reinforce the therapeutic alliance. These factors would be possible moderators of control group efficacy related to the reduction in depressive symptoms and a decrease in mortality and events.

Conclusion: In the reviewed studies, we found that the control condition was beneficial for CAD patients, but this benefit was highly variable. Specified psychotherapeutic interventions showed an additional independent effect of treatment on depression and effects on morbidity and mortality. There is a need to identify patients at risk of remaining depressed or under severe stress during usual care. These patients may require additional psychosocial intervention.