Table 1.

Description of behavioural questionnaires used including questionnaire constructs, domains and details of scoring.

Name	Construct Intended to measure	Domains	Scoring	Comments
Numeric Rating Scale (NRS)	Pain intensity	n/a	11 point scale, 0–10
Short Form McGill Pain Questionnaire (SFMPQ) (Melzack, 1987)	Multidimensional measure of pain	Measures a) sensory and b) affective dimensions of the pain experience. Also includes five-item present pain intensity scale (PPI) to describe overall pain intensity and 10-cm visual analogue scale (VAS).	Intensity scale from 0 (none) to 4 (severe).	Widely used in adult chronic pain populations, including CLBP (Ruoff et al., 2003) and has modest predictability in discrimination of neuropathic and musculoskeletal pain of spinal cord injury (Putzke et al., 2002).
Rand Medical Outcomes 36-Item Short Form Survey Instrument (SF-36) (Ware and Sherbourne, 1992)	General health related quality of life questionnaire.	Measures: 1) limitations in physical activities because of health problems (SF-36 Physical Function); 2) limitations in social activities because of physical or emotional problems (SF-36 Social Function); 3) limitations in usual role activities because of physical health problems (SF-36 Role-Physical); 4) bodily pain (SF-36 Pain); 5) psychological distress and emotional well-being (SF-36 General Mental Health); 6) limitations in usual role activities because of emotional problems (SF-36 Role-Emotional); 7) energy and fatigue (SF-36 Vitality); 8) general health perceptions (SF-36 General Health).	For each of the eight domains an aggregate percentage score is produced. The percentage scores range from 0% (lowest or worst possible level of functioning) to 100% (highest or best possible level of functioning). Two summary scores of physical quality of life (Physical Component Summary; PCS) and psychological well-being and general health perception (Mental Component summary; MCS) can also be obtained by combining physical and mental domains respectively (Ware et al., 1995). PCS and MCS scales are scored to have the same average (50) and standard deviation (10) (norm-based scores). Therefore scores below and above 50 represent above and below average values of physical and mental health and functioning with increasingly low scores represent increasing degrees of psychological distress and disability (Ware et al., 1993). A cut off score of 35 or less on the MCS is able to identify depressive symptoms (as measured by the CES-D) in LBP patients (Walsh et al., 2006).	Widely used measure of health-related quality of life; has been shown to discriminate between subjects with different chronic conditions and between subjects with different severity levels of the same disease (Kosinski et al., 1999)
Centre For Epidemiologic Studies Depression Scale Questionnaire (CES-D) (Radloff, 1977)	20-item questionnaire of symptoms associated with depression		Scores range from 0 to 60, with high scores indicating greater depressive symptoms. It cannot be used to diagnose depression in itself. However, scores of 16 or greater can be used to identify individuals at risk for clinical depression in primary care and 19 or greater in the chronic pain population (Turk and Okifuji, 1994).
State Trait Anxiety Inventory (STAI) (Spielberger, 1983)	Anxiety	Measures two components of anxiety: Anxiety in the present moment (“state”) and anxiety as a general, ongoing personal characteristic (“trait”).	Twenty questions are each scored on a four point Likert scale; higher scores are associated with higher levels of anxiety. A cut-point of 39–40 is normally used for clinically significant symptoms of a state of anxiety (Julian, 2011, Knight et al., 1983)
Revised Symptom Checklist 90 Questionnaire (SCL-90-R) (Derogatis and Unger, 2010)	The SCL-90 is designed to assess a broad range of psychological problems and the current psychopathology of subjects along nine symptom constructs.	Symptom constructs: Somatisation, Obsessive-Compulsive Symptoms, Interpersonal Sensitivity, Depression, Anxiety, Hostility, Phobic-Anxiety, Paranoid Ideation and Psychoticism. Three additional scales have also been developed; the Positive Symptom Total (PST) measuring the total number of self reported symptoms, the Positive Symptom Distress Index (PSDI) measuring intensity of symptoms and the Global Severity Index (GSI), designed to measure overall psychological distress which can be used as a summary of the test.	90-item questionnaire: Raw scores are calculated by dividing the sum of scores for a domain by the number of items in the domain. The global severity index is computed by summing the scores of the nine domains and additional items and then dividing by the total number of responses. Scores are converted to standard T-scores using the norm group appropriate for the patient. The SCL-90-R scoring manual contains normative data for psychiatric outpatients, psychiatric inpatients, adult non-patients, adolescent non-patients (http://www.pearsonclinical.co.uk) (Schmitz et al., 2000)