Supplementary Material for: Bypass Surgery with Psychological and Spiritual Support (the BY.PASS Study): Results of a Pragmatic Trial Based on Patients’ Preference

<b><i>Background:</i></b> Some general hospitals within the German health system provide supportive interventions, psychological as well as spiritual, to their patients. It remains to be proven if these interventions are effective when used in routine clinical practice. <b><i>Aim:</i></b> To evaluate the effectiveness of psychological and spiritual interventions on improving recovery following bypass surgery. <b><i>Methods:</i></b> The BY.PASS study is a pragmatic, patient preference trial (ISRCTN 07297983). Adult patients scheduled for elective coronary bypass surgery were enrolled. Patients were assigned to study conditions according to their personal preference: preference for psychological interventions, for spiritual interventions or for no intervention. Patients who were open for any kind of intervention were randomly assigned either to psychological or spiritual interventions. During a control period, patients were asked about their preference, but did not receive any interventions. Primary outcomes of the study were in-hospital morbidity and early mortality. Psychological measures served as secondary outcomes. <b><i>Results:</i></b> A total of 847 patients were enrolled. Patients of the control (n = 260) and the intervention group (n = 269) who explicitly wanted to have interventions were compared. No significant treatment effects either for morbidity (d = 0.08, 95% CI –0.09 to 0.25), or for mortality (OR = 1.81; 95% CI 0.50–6.57) could be found. A reduction of negative mood resulted from both interventions. <b><i>Conclusions:</i></b> Although the effects observed were small, the study can serve as a basis to discuss methodological as well as theoretical aspects of a pragmatic trial, based upon patients’ preferences