Table 2 Measures of the randomized controlled trial of BRIA; Kerper et al., Effects of an innovative psychotherapy program for surgical patients - Bridging Intervention in Anesthesiology: A randomized controlled trial. Anesthesiology 2015;123:148-59 [6]

Computer assisted preoperative self-assessment to measure clinically significant psychological distress and psychosocial factors

World Health Organization 5-item Well-Being Index (WHO-5): Short depression / well-being screening tool of the WHO. Time frame: Past 14 days. Scaling: 5 items, 6-point scale from 0 to 5; total score from 0 to 25; Cut-off: WHO-5 sum score < 14 [51].

Patient Health Questionnaire-4 (PHQ-4): Ultra-brief screening tool with subscales for depression (PHQ-2), and generalized anxiety (GAD-2). Time frame: Past 14 days. Scaling: 5 items, 4-point scale from 0 to 3; Sum scores of PHQ-2 and GAD-2 ranging from 0 to 6, with cut-off’s for both subscales of ≥3 [52].

Hospital Anxiety and Depression Scale (HADS): Short screening tool with subscales for depression (HADS-D) and anxiety (HADS-A). Time frame: Past 7 days. Scaling: 14 items, 4-point scale from 0 to 3; for HADS-D and HADS-A each 7 items. Sum scores ranging from 0 to 21 with cut-off’s for HADS-D ≥ 9, HADS-A ≥ 11 [53].

Alcohol Use Disorder Identification Test (AUDIT): WHO screening tool for hazardous and harmful alcohol consumption, and alcohol-related problems. Time frame: Past 12 months. Scaling: 10 items, 5-point scale from 0 to 4; total score from 0 to 40. Cut-off: AUDIT sum score: ≥8 for men; ≥5 for women [54].

Single items: Tobacco smoking, use of illicit drugs, loneliness, sleeping disturbance, physical activity, weight / height, pain, use of psychoactive medication, participation in psychosocial / addiction therapy.

Postoperative questionnaires, interviews and medical scores to measure clinical characteristics, outcomes and moderator variables

Semistructured interview including the Short Diagnostic Interview for Mental Disorders (MiniDIPS): Diagnoses of mental disorders according to ICD-10; anxiety, mood, adjustment, trauma-related, obsessive-compulsive, somatoform, eating, and substance use disorders; screening questions for psychotic disorders [44].

University of Rhode Island Change Assessment (URICA): Self-report questionnaire measuring motivational readiness to change according to the transtheoretical model of change. Time frame: Current state. Scaling: 16 items, 5-point scale from 1 to 5; composite measure of readiness to change from −2 to 14 [62, 63].

Brief Symptom Inventory (BSI): Self-report questionnaire measuring diverse symptoms of psychological distress. Time frame: Past 7 days. Scaling: 53 items, 5-point scale from 0 to 4. Total mean score Global Severity Index (GSI) from 0 to 4 [42, 43].

Semistructured telephone interview assessing 2 measures of therapy engagement: (1) Participation in psychosocial mental health care, defined as undergoing, being on a waiting list or having completed a psychosocial mental health care program other than BRIA itself during the 6 months after inclusion in the trial. (2) Having approached a psychosocial mental health care program regardless of whether this approach resulted in a participation in therapy sessions or a place on a waiting list.

Medical measures: (1) Preoperative physical health status according to the ASA (American Society of Anesthesiologists) physical status classification system [46, 47]; (2) Surgical field: neuro-, head and neck surgery; abdomino-thoracic surgery; peripheral surgery [5, 65,66,67]; (3) Severity of medical comorbidity according to the Charlson Comorbidity Index (CCI) [48]; (4) Extent of the specific surgical procedures according to the 4-point item ‘operative severity’ of the POSSUM scoring system (Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity) [49, 50].