Table 4.

Participant-reported outcome measures (PROMs).

OMERACT Domain and Outcome Measures	Tool Background, Use and Scoring
‘Core’ Domains:
Multidimensional function FIQR (i) (2009, replacing FIQ)	Recommended outcome measure in assessment of ‘multidimensional function’ or health-related quality of life [54]. A total of 21 questions across 3 domains: ‘function’, ‘overall impact’, ‘symptoms’. Each question requires a score based on an 11-point NRS pertaining to previous seven days, with a score of 0 being the ‘best’ and 10 being ‘worst’. Administrator calculates overall score. Nine questions from Domain 1 are totalled and divided by 3. Two questions from Domain 2 are simply added. Ten questions from Domain 3 are totalled and divided by 2. The final sum of resulting 3 figures represents the total (0 to 100). Higher scores indicate increased severity of FM [55].
Pain BPI-SF (ii) (1994)	Distinguishes pain into two components in preceding 24 h—pain intensity and pain interference [56]. The recommended pain assessment tool in FM clinical trials [54]. ‘Sensory dimension’: asked to rate ‘worst’, ‘least’, ‘average’, ‘pain now’ on 11-point NRS. ‘Reactive dimension’: score extent pain has interfered with mood, walking and other physical activity, work, social activity, relations with others, and sleep (0 = ‘does not interfere’, 10 = ‘completely interferes’) [56]. Four pain-intensity and seven pain-interference results averaged to give overall pain-intensity score and pain-interference score (0 to 10), respectively [57,58,59].
WPI + SSS (iii) (2010, updated 2016)	Updated diagnostic tool and a potential alternative [59] to original tender point examination, 1990 [60]. WPI: tick painful anatomical areas in preceding week. Nineteen areas are listed across 5 anatomical regions; 4 of which need to be ‘positive’ for an initial diagnosis of FM to be met. SSS: scored out of maximum of 12. Encompasses array of symptoms—user asked to report their presence and/or severity. Total potential combined WPI-SSS score is 31—higher scores indicate more severe FM [59]. Updated 2016 version: for user to be positive for FM diagnosis must score WPI ≥ 7 and SSS ≥ 5, or WPI 4–6 and SSS ≥ 9 [61].
Fatigue FSS (iv) (1989)	Unidimensional generic fatigue rating scale [62], emphasises functional impact of fatigue [63]. The recommended fatigue assessment tool for FM [54]. Nine fatigue-related questions, each scored on a 7-point Likert agreement scale (1 to 7). Resultant score is average of 9 scores, with maximum possible score of 7—indicating the most severe fatigue-related symptoms and intrusiveness.
Sleep disturbance JSQ (v) (1988)	Four-item self-report questionnaire designed to measure frequency of sleep problems in past month. The recommended assessment tool to evaluate sleep in FM patients [54]. A 5-point Likert scale (0 = ‘not at all’ to 5 = ‘22–31 days’) was utilised to evaluate the number of days/month that specific sleep-related issues occur (trouble falling and staying asleep, waking up several times/night, waking up after usual amount of sleep feeling tired and worn out). Maximum possible score is 20. Higher scores indicate higher frequency of sleep problems [64].
Patient Global PGIC (vi) (1970s)	Self-report global change questionnaire: 7-point NRS (1 to 7) to determine degree of change following a treatment from patients’ own perspective. Score of ‘1’ indicates either no change or worsening symptoms since treatment. A ‘7’ indicates the patient feels ‘great deal better, considerable improvement that has made all the difference’ [65]. IMMPACT (Initiative on Methods, Measurement and Pain Assessment in Clinical Trials) recommended for evaluating participant ratings of overall improvement in pain treatment trials [65]. Specifically recommended in the assessment of global improvement of FM patients in conjunction with the FIQR [54].
‘Peripheral’ Domains:
Anxiety HADS (vii) (1983) Anxiety subsection (HADS-A)	A 14-item measure: each item rated on a 4-point severity scale (0 to 3). HADS-A subscales: comprised of 7 items. Acknowledged to have been used in FM trials assessing medication efficacy [54].
Depression HADS (vii) Depression subsection (HADS-D)	HADS-D subscales: comprised of 7 items. Scores range from 0 to 21. Higher scores indicate more severe symptoms [66,67]. The recommended tool for assessment of depressive symptoms in FM patients [54].
Stiffness Subsection of FIQR (i)
Dyscognition Subsection of FIQR (i)

(i) FIQR (Revision Fibromyalgia Impact Questionnaire), (ii) BPI-SF (Brief Pain Inventory—Short Form), (iii) WPI-SSS (Widespread Pain Index—Symptom Severity Score), (iv) FSS (Fatigue Severity Scale), (v) JSQ (Jenkins Sleep Questionnaire), (vi) PGIC (Patient Global Impression of Change), (vii) HADS (Hospital Anxiety and Depression Score).