Risk factors for development and persistence of chronic widespread pain in spondyloarthritis: a population-based two-year follow-up study

Figures & data

Figure 1. Transition of patients to and from the pain groups between 2009 and 2011. NCP, no chronic pain; CRP, chronic regional pain; CWP, chronic widespread pain.

Table 1. Patient characteristics and differences for the subgroups ankylosing spondylitis (AS) (n = 433) and undifferentiated spondyloarthritis (USpA) (n = 279) in 2009 and 2011.

	2009			2011
	AS	USpA	p	AS	USpA	p
Age (years)	54.8 ± 13.2	50.3 ± 12.9	≤ 0.001
Female gender	164 (38)	167 (60)	≤ 0.001
Disease duration (years)	28.0 ± 13.8	17.2 ± 11.2	≤ 0.001
Diagnosis delay (years)	7.4 ± 7.6	6.5 ± 8.7	0.205
sDMARDs	87 (20.1)	58 (20.8)	0.392	73 (16.9)	59 (21.1)	0.697
bDMARDs	84 (19.4)	41 (14.7)	0.007	95 (21.9)	46 (16.5)	0.017
Prednisolone	43 (9.9)	44 (15.8)	0.399	41 (9.5)	39 (14.0)	0.297
BMI (kg/m^2)
18.5‒24.9	180 (43.5)	130 (48.3)	0.418†	168 (42.1)	119 (45.8)	0.331†
25‒29.9	175 (42.3)	101 (37.5)		178 (44.6)	101 (38.8)
≥ 30	59 (14.3)	38 (14.1)		53 (13.3)	40 (15.4)
Smoking
Never smoker	193 (44.6)	167 (60.1)	≤ 0.001†	191 (45.2)	168 (60.9)	≤ 0.001†
Ever smoker	240 (55.4)	111 (39.9)		232 (54.8)	108 (39.1)
Pain regions, n	4.4 ± 4.5	5.2 ± 4.8	0.032	4.6 ± 4.7	5.4 ± 4.8	0.033
Pain (0‒10)	3.7 ± 2.5	4.0 ± 2.5	0.155	4.0 ± 2.5	4.1 ± 2.5	0.438
Fatigue (0‒10)	4.4 ± 2.7	4.7 ± 2.8	0.249	4.9 ± 2.7	5.0 ± 2.8	0.516
Global health (0‒10)	3.9 ± 2.3	3.9 ± 2.4	0.812	4.2 ± 2.4	4.1 ± 2.4	0.591
EQ-5D, UK (0‒1)	0.67 ± 0.25	0.67 ± 0.25	0.942	0.65 ± 0.28	0.67 ± 0.25	0.528
BASDAI (0‒10)	3.9 ± 2.2	4.2 ± 2.2	0.059	3.7 ± 2.2	4.0 ± 2.2	0.148
BASFI (0‒10)	3.3 ± 2.5	2.9 ± 2.3	0.066	3.5 ± 2.7	3.0 ± 2.4	0.011
ASES–Pain (10‒100)	51.8 ± 21.7	52.3 ± 21.2	0.764	50.5 ± 21.4	52.7 ± 21.2	0.170
ASES–Symptom (10‒100)	59.0 ± 20.5	58.0 ± 20.5	0.524	58.0 ± 20.5	59.3 ± 21.0	0.401
HADS anxiety (0‒21)	5.8 ± 4.1	5.7 ± 4.0	0.806	5.7 ± 4.4	5.4 ± 4.4	0.402
HADS depression (0‒21)	4.2 ± 3.4	4.3 ± 3.6	0.786	4.3 ± 3.6	4.2 ± 3.8	0.786

Data are shown as mean ± sd or n (%).

sDMARD, synthetic disease-modifying anti-rheumatic drug (salazopyrin, methotrexate); bDMARD, biological disease-modifying anti-rheumatic drug (Enbrel, Humira, Remicade, and in addition Simponi in 2011); BMI, body mass index; EQ-5D, EuroQoL 5 Dimensions; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Functional Index; ASES, Arthritis Self-Efficacy Scale; HADS, Hospital Anxiety and Depression Scale.

†Adjusted for all variables in the table.

Table 2. Characteristics of women (n = 331) and men (n = 381) with spondyloarthritis, 2009 and 2011.

	2009			2011
	Women	Men	p	Women	Men	p
Age (years)	51.2 ± 13.6	54.6 ± 12.9	0.001
Disease duration (years)	21.0 ± 13.3	26.3 ± 13.9	≤ 0.001
Diagnosis delay (years)	8.0 ± 8.3	6.4 ± 7.7	0.014
sDMARDs	71 (21.5)	74 (19.4)	0.727	67 (20.2)	65 (17.1)	0.580
bDMARDs	56 (16.9)	69 (18.1)	0.077	61 (18.4)	80 (21.0)	0.097
Prednisolone	46 (13.9)	41 (10.8)	0.841	45 (13.6)	35 (9.2)	0.259
BMI (kg/m^2)
18.5‒24.9	169 (53.5)	141 (38.4)	≤ 0.001†	146 (47.7)	141 (39.9)	0.134†
25‒29.9	107 (33.9)	169 (46.0)		120 (39.2)	159 (45.0)
≥ 30	40 (12.7)	57 (15.5)		40 (13.1)	53 (15.0)
Smoking
Never smoker	185 (55.9)	175 (46.1)	0.009†	187 (57.5)	172 (46.0)	0.002†
Ever smoker	146 (44.1)	205 (53.9)		138 (42.5)	202 (54.0)
Pain regions, n	5.6 ± 4.8	4.0 ± 4.4	≤ 0.001	5.9 ± 4.9	4.1 ± 4.5	≤ 0.001
Pain (0‒10)	4.3 ± 2.5	3.4 ± 2.4	≤ 0.001	4.4 ± 2.4	3.8 ± 2.5	0.003
Fatigue (0‒10)	5.0 ± 2.8	4.1 ± 2.7	≤ 0.001	5.4 ± 2.7	4.5 ± 2.7	≤ 0.001
Global health (0‒10)	4.2 ± 2.3	3.6 ± 2.3	0.001	4.3 ± 2.3	3.9 ± 2.4	0.001
EQ-5D, UK (0‒1)	0.65 ± 0.3	0.69 ± 2.3	0.105	0.65 ± 0.3	0.67 ± 0.3	0.450
BASDAI (0‒10)	4.4 ± 2.2	3.7 ± 2.1	≤ 0.001	4.3 ± 2.2	3.5 ± 2.2	≤ 0.001
BASFI (0‒10)	3.4 ± 2.4	3.0 ± 2.5	0.300	3.4 ± 2.5	3.2 ± 2.6	0.439
ASES–Pain (10‒100)	52.2 ± 21.6	51.8 ± 21.5	0.817	52.0 ± 21.2	50.8 ± 21.4	0.463
ASES–Symptom (10‒100)	57.5 ± 19.4	59.5 ± 21.3	0.198	58.0 ± 19.6	59.0 ± 21.6	0.556
HADS anxiety (0‒21)	6.1 ± 3.9	5.5 ± 4.2	0.034	5.9 ± 4.4	5.4 ± 4.4	0.161
HADS depression (0‒21)	4.3 ± 3.5	4.2 ± 3.5	0.675	4.1 ± 3.5	4.4 ± 3.8	0.212

Data are shown as mean ± sd or n (%).

sDMARD, synthetic disease-modifying anti-rheumatic drug (salazopyrin, methotrexate); bDMARD, biological disease-modifying anti-rheumatic drug (Enbrel, Humira, Remicade, and, in addition, Simponi in 2011); BMI, body mass index; EQ-5D, EuroQoL 5 Dimensions; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Functional Index; ASES, Arthritis Self-Efficacy Scale; HADS, Hospital Anxiety and Depression Scale.

†Adjusted for all variables in the table.

Table 3. Results from the multiple logistic regression analysis with patients who had developed chronic widespread pain at follow-up (2011), compared to those who still reported no chronic pain or chronic regional pain.

Variable	n	OR (95% CI)	p
Age (per 1 year)	340	1.02 (1.00–1.04)	0.075
Gender
Men	201	1
Women	139	1.32 (0.80–2.18)	0.276
SpA subgroup
AS	210	1
USpA	130	1.42 (0.85–2.36)	0.179
Disease duration (years)	323	1.00 (0.97–1.02)	0.754
BMI (kg/m^2)
18.5–24.9	162	1
25–29.9	132	0.98 (0.57–1.68)	0.941
≥ 30	33	1.36 (0.60–3.10)	0.460
Smoking
Never smoker	191	1
Ever smoker	148	1.25 (0.76–2.07)	0.383
Pain regions, n	340	1.36 (1.20–1.53)	≤ 0.001
Pain (0–10)	339	1.35 (1.20–1.52)	≤ 0.001
Fatigue (0–10)	338	1.25 (1.13–1.38)	≤ 0.001
Global health (0–10)	337	1.35 (1.19–1.54)	≤ 0.001
EQ-5D (0–1)	334	0.05 (0.01–0.19)	≤ 0.001
BASDAI (0–10)	281	1.25 (1.07–1.45)	0.004
BASFI (0–10)	335	1.32 (1.16–1.50)	≤ 0.001
ASES–Pain (10–100)	335	0.97 (0.96–0.99)	≤ 0.001
ASES–Symptom (10–100)	334	0.98 (0.97–0.99)	0.001
HADS anxiety (0–21)	340	1.06 (0.99–1.13)	0.081
HADS depression (0–21)	340	1.10 (1.02–1.19)	0.011

Age, gender, and spondyloarthritis (SpA) subgroup [ankylosing spondylitis (AS) and undifferentiated spondyloarthritis (USpA)] were included in all analyses, and all other variables were added separately and controlled for age, gender, and diagnosis.

BMI, body mass index; EQ-5D, EuroQoL-5 dimensions; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Functional Index; ASES, Arthritis Self-Efficacy Scale; HADS, Hospital Anxiety and Depression Scale; OR, odds ratio; CI, confidence interval.

Table 4. Results from the multiple logistic regression analysis with patients who reported having persistent chronic widespread pain at follow-up (2011), compared to those who had improved to no chronic pain or chronic regional pain.

Variable	n	OR (95% CI)	p
Age (per 1 year)	304	1.02 (1.00–1.04)	0.040
Gender
Men	142	1
Women	162	1.82 (1.06–3.10)	0.029
SpA subgroup
AS	176	1
USpA	128	1.39 (0.80–2.41)	0.237
Disease duration (years)	285	1.01 (0.99–1.04)	0.293
BMI (kg/m^2)
18.5–24.9	120	1
25–29.9	118	1.17 (0.65–2.10)	0.607
≥ 30	54	1.19 (0.56–2.50)	0.656
Smoking
Never smoker	145	1
Ever smoker	159	0.89 (0.53–1.51)	0.674
Pain regions, n	304	1.23 (1.12–1.35)	≤ 0.001
Pain (0–10)	304	1.32 (1.16–1.49)	≤ 0.001
Fatigue (0–10)	304	1.26 (1.13–1.40)	≤ 0.001
Global health (0–10)	304	1.33 (1.17–1.51)	≤ 0.001
EQ-5D (0–1)	279	0.21 (0.07–0.63)	0.005
BASDAI (0–10)	283	1.30 (1.12–1.50)	≤ 0.001
BASFI (0–10)	299	1.26 (1.12–1.42)	≤ 0.001
ASES–Pain (10–100)	301	0.98 (0.97–0.99)	0.007
ASES–Symptom (10–100)	299	0.98 (0.96–0.99)	0.002
HADS anxiety (0–21)	303	1.07 (1.00–1.14)	0.036
HADS depression (0–21)	303	1.09 (1.01–1.17)	0.034

Age, gender, and spondyloarthritis (SpA) subgroup [ankylosing spondylitis (AS) and undifferentiated spondyloarthritis (USpA)] were included in all analyses, and all other variables were added separately and controlled for age, gender, and diagnosis.

BMI, body mass index; EQ-5D, EuroQoL-5 dimensions; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Functional Index; ASES, Arthritis Self-Efficacy Scale; HADS, Hospital Anxiety and Depression Scale; OR, odds ratio; CI, confidence interval.