Table 1 Variables and methods used to assess clinical manifestations of chronic non-specific musculoskeletal pain

Chronic Pain Grade Questionnaire (CPG)* [65, 66]

Severity of chronic pain problems (disability, pain intensity)

Pain Experience Scale (SES) [64]

Sensory and affective descriptors of pain

12-Item Short-Form Health Survey (SF-12)* [74, 75]

Health-related quality of life

Resilience Scale (RS11)* [97, 98]

Resilience (personal competence, acceptance of self and life)

Hospital Anxiety and Depression Scale (HADS-D)* [99, 100]

Anxiety and depression

Childhood Trauma Questionnaire (CTQ)* [72, 73, 101]

Childhood and adolescence maltreatment (physical and emotional abuse, sexual abuse, physical and emotional neglect)

Pain drawing (pain location) [62][63][6]

Perceived location(s) of pain will be assessed using digitised pain drawings. Classification into categories of chronic local and chronic widespread pain.

Sociodemographics (self-report questions)

Age, sex, marital status, education, employment status

Interviews

Structured Clinical Interview for DSM-IV Axis I Disorders + Axis II (SCID I + II)* [69]

DSM-IV Axis-I and Axis-II mental disorders

Physical examination

ACR Criteria for Fibromyalgia (ACR Classification) [62][102]

Tenderpoint count and documentation of specific symptoms

Physical Impairment Scale (PIS) [67]

Physical impairment (total flexion, total extension, average lateral flexion, straight leg raising, spinal tenderness, bilateral active straight leg raising, and sit-up)

Back Performance Scale (BPS) [68]

Disability. Tests of daily activities (Sock Test, Pick-up Test, Roll-up Test, Fingertip-to-Floor Test, and Lift Test)