Download Appendix 1. Description of Psychometric Scales Short

Appendix 1. Description of Psychometric Scales
1. Short-form McGill Pain Questionnaire 2 (SFMPQ2):18 This is a scale which asks participants to
rate each of 22 pain descriptors on a scale from 0 (none) to 10 (worst possible). A total score is
determined by calculating the average score over all 22 items. The SFMPQ2 has been
demonstrated to have excellent reliability and validity.19
2. Pain Numerical Rating Scale: Participants were asked to rate their average pain level over the
past 2 days on a scale from 0 (no pain) to 10 (worst pain you can imagine).
3. Disability: Pain Disability Index:20 This 7-item scale asks participants to rate their level of
disability for 7 domains of life on a scale from 0 (no disability) to 10 (total disability). A total
disability score out of 70 is calculated by adding the items together. Higher scores represent
greater disability. This scale has been shown to have good psychometric properties, although
most of the research to date on this scale has been conducted in low back pain patients rather
than limb pain patients.21
4. Pain-related fear: Tampa scale for Kinesiophobia:22 This is an 11-item scale which asks
participants to rate the extent to which they agree or disagree with a range of statements
endorsing pain-related fear. Scores are calculated between a minimum of 11 (no pain-related
fear) and a maximum of 44 (high levels of pain-related fear). This scale has been demonstrated
to have good reliability and validity.22
5. Catastrophic thinking: Pain Catastrophizing Scale:23 This is a 13-item scale which asks
participants to rate the extent to which they experience a range of catastrophic thoughts on a 5
point scale from 0 (not at all) to 4 (all the time). A total score out of 52 is calculated by summing
all answers together. Higher scores indicate greater levels of pain catastrophizing. The scale has
been shown to have excellent reliability and validity.23
6. Depression Anxiety Stress Scale 21:24 This 21-item scale consists of 7 items measuring
depression , 7 measuring anxiety, and 7 measuring stress. Participants are asked to rate the
extent to which they endorse each item on a scale from 0 (did not apply to me at all) to 3
(applied to me very much or most of the time). Items for each of the three subscales are added
together to give three scores, each out of 21, with higher scores representing greater distress.
The DASS has been shown to have very good reliability and validity.24 Clinical cut-off scores for
normal, mild, moderate, severe and extremely severe depression, anxiety and stress have also
been published.25