Rethinking the criteria for fibromyalgia in 2019: the ABC indicators

Figures & data

Figure 1 The fibromyalgia syndrome and the ABC indicators within the context of functional pain syndromes and rheumatological diseases.

Figure 2 Pain drawing example of bilateral axial-symmetric pain distribution.

Table 1 Health characteristics of 409 patients with functional pain syndromes according to their anatomical pain distribution patterns

Functional pain syndromes	Non-whole-body variant	Whole-body variant
Subsample size (n)	240 (58.7%)	169 (41.3%)
Age (years)	47.1 (±13.4)	48.2 (±10.6)	n.s.
Sex (male)	47.5% (114/240)	40.2% (68/169)	n.s.
Time since pain first occurred (months)	88.9 (±134.0)	106.00 (±110.4)	n.s.
Average pain intensity (NRS 0–10)	6.5 (±1.8)	6.78 (±2.0)	n.s.
FM 2011 criteria	31.9% (76/238)	75.5% (120/159)	***
ABC indicators (for details see Tables 3 and 4)	11.7% (26/222)	62.3% (86/138)	***

Notes: Mean (± SD). ***p<0.001. t-tests and chi-square tests were implemented to test for significant differences between groups.

Abbreviations: NRS, numerical rating scale, n.s., not significant.

Table 2 Differences in FM characteristics between non-whole-body and whole-body variants

	Non-whole-body pain	Whole-body pain	Odds ratio or Cohen’s d	p-value
WPI	4.54 (±3.21)	9.23 (±4.06)	1.28	0.001
Indicator A (hyperalgesia)	48.1%	69.8%	1.91	0.009
Pain sensitivity middle finger	3.46 (±2.64)	4.41 (±2.87)	0.34	0.002
Pain sensitivity earlobe	6.91 (±2.99)	7.85 (±2.84)	0.32	0.005
Indicator B (bilateral pain)	30.0%	94.7%	41.57	0.001
Indicator C (chronic distress)
HADS total distress	18.60 (±8.93)	20.42 (±9.21)	0.20	0.049
HADS depression	9.39 (±4.96)	9.82 (±4.77)	0.09	0.390
HADS anxiety	9.21 (±4.92)	10.59 (±5.28)	0.27	0.009
BSI total	0.96 (±0.66)	1.13 (±0.67)	0.26	0.020
BSI depression	1.06 (±0.98)	1.17 (±0.97)	0.11	0.300
BSI anxiety	1.04 (±0.83)	1.30 (±0.84)	0.30	0.006
SSS 2011	6.61 (±2.49)	7.66 (±2.14)	0.45	0.001

Abbreviations: HADS, Hospital Anxiety and Depression Scale; BSI, Brief Symptom Inventory; WPI, Widespread Pain Index; SSS, Symptom Severity Scale.

Table 3 Pearson correlations among SSS 2011 and indicator C (distress) measures

	Correlation coefficient r
HADS-total distress	0.33***
HADS-depression	0.32***
HADS-anxiety	0.29***
BSI-total	0.42***
BSI-anxiety	0.36***
BSI-depression	0.32***

Note: ***p<0.001.

Abbreviations: SSS, Symptom Severity Scale; HADS, Hospital Anxiety and Depression Scale; BSI, Brief Symptom Inventory.

Table 4 Sensitivity, specificity, correct classification and DOR

	Non-whole-body variants(True-negative specificity)	Whole-body variants (True-positive sensitivity)	Correct classification rate	DOR
FM 2011 criteria	68.1%	75.5%	71.0%	6.56 (CI: 4.17–10.31)
ABC indicators	88.3%	62.3%	78.3%	12.47 (CI: 7.30–21.28)

Abbreviations: CI, confidence intervals; DOR, diagnostic odds ratio.