Table 2.

Multivariable logistic regression analyses with PCS score below the median value as dependent variable

	All, n = 210 PCS < median PCS 42.4			Men, n = 121 PCS < median PCS 43.6			Women, n = 89 PCS < median PCS 41.8
Variables	OR	95% CI	P value	OR	95% CI	P value	OR	95% CI	P value
BMI, kg/m2	1.03	0.93 to 1.14	0.55	0.98	0.84 to 1.14	0.78
Civil state, single	2.38	1.00 to 5.67	0.049	3.28	0.94 to 11.52	0.063	3.07	0.83 to 11.40	0.094
Years in school, < 13 years	1.12	0.50 to 2.48	0.79	1.40	0.43 to 4.55	0.57
Ever smoker	0.77	0.35 to 1.73	0.53	0.55	0.16 to 1.89	0.34
VAS global fatigue, > median	1.04	0.46 to 2.38	0.92	2.23	0.66 to 7.56	0.20
Duration of symptoms, decades	1.66	1.16 to 2.37	0.005	1.36	0.81 to 2.30	0.24	1.69	0.99 to 2.90	0.055
ESR, > median	0.98	0.45 to 2.10	0.95
BASMI, units							0.72	0.38 to 1.34	0.30
Lateral spinal flexion, cm	0.99	0.90 to 1.09	0.86	0.92	0.80 to 1.06	0.27
BASFI, unit	1.98	1.46 to 2.70	< 0.001	2.09	1.29 to 3.41	0.003	2.25	1.42 to 3.57	0.001
ASDAS-CRP, ≥ 2.1	3.32	1.45 to 7.62	0.005	4.87	1.46 to 16.27	0.010	1.83	0.51 to 6.53	0.36
Log10mSASSS + 1, score	0.74	0.36 to 1.54	0.43
≥ 3 intervertebral bridges consecutively (only men)a				0.57	0.12 to 2.70	0.48

Significant differences are in bold text. The independent variables were defined by having a univariate association with PCS (p-value ≤0.2) and not demonstrating collinearity. Due to some missing data, the models are based on an overall 203 patients and in stratified analyses 115 men and 86 women

PCS physical component summary, OR odds ratio, CI confidence interval, BMI body mass index, VAS visual analogue scale, ESR erythrocyte sedimentation rate, BASMI Bath Ankylosing Spondylitis Metrology Index, BASFI Bath Ankylosing Spondylitis Functional Index, ASDAS-CRP Ankylosing Spondylitis Disease Activity Score C-reactive protein, mSASSS Modified Stoke Ankylosing Spondylitis Spine Score ^aCervical and/or lumbar spine