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Table 2 Descriptive statistics of baseline measures

From: Psychometric validation of the EuroQoL 5-dimension (EQ-5D) questionnaire in patients with spondyloarthritis

  Mean ± SD Observed range Theoretical range Cronbach’s alpha Floor Ceiling
ODI score 19.1 ± 15.6 (0.0, 66.0) (0.0, 100.0) 0.895 1.4% (3) 0.0% (0)
HADS score
 Depression 5.0 ± 3.7 (0.0, 19.0) (0.0, 21.0) 0.835 5.8% (12) 0.0% (0)
 Anxiety 5.8 ± 3.7 (0.0, 16.0) (0.0, 21.0) 0.860 4.8% (10) 0.0% (0)
 Total 10.8 ± 6.9 (0.0, 35.0) (0.0, 42.0) 0.908 3.9% (8) 0.0% (0)
EQ-5D VAS score 62.9 ± 18.9 (10.0, 97.0) (0.0, 100.0) NA 0.0% (0) 0.0% (0)
EQ-5D-5 L score 0.789 ± 0.191 (− 0.044, 1.000) (− 0.391, 1.000) 0.843 0.0% (0) 3.2% (7)
BASFI 2.2 ± 2.2 (0.0, 8.9) (0.0, 10.0) 0.940 6.4% (14) 0.0% (0)
BASMI 4.0 ± 1.6 (0.7, 8.2) (0.0, 10.0) 0.806 0.0% (0) 0.0% (0)
SF-36
 Physical functioning 74.2 ± 20.4 (5.0, 100.0) (0.0, 100.0) 0.900 0.0% (0) 7.4% (12)
 Role physical 70.7 ± 23.4 (0.0, 100.0) (0.0, 100.0) 0.941 0.0% (0) 13.5% (22)
 Role emotional 72.5 ± 25.3 (0.0, 100.0) (0.0, 100.0) 0.936 0.0% (0) 16.0% (26)
 Vitality 52.7 ± 19.7 (0.0, 93.8) (0.0, 100.0) 0.792 0.6% (1) 0.0% (0)
 Emotional well-being 67.0 ± 17.6 (20.0, 100.0) (0.0, 100.0) 0.819 0.0% (0) 1.9% (3)
 Social functioning 77.4 ± 22.0 (12.5, 100.0) (0.0, 100.0) 0.846 0.0% (0) 17.3% (28)
 Bodily pain 61.9 ± 22.3 (10.0, 100.0) (0.0, 100.0) 0.852 0.0% (0) 1.9% (3)
 General health 42.0 ± 20.1 (0.0, 95.0) (0.0, 100.0) 0.823 1.3% (2) 0.0% (0)
 PCS 44.2 ± 8.2 (19.5, 60.7) (0.0, 100.0) 0.959 0.0% (0) 0.0% (0)
 MCS 45.5 ± 10.6 (17.3, 71.1) (0.0, 100.0) 0.959 0.0% (0) 0.0% (0)
BASDAI 3.5 ± 2.0 (0.0, 9.2) (0.0, 10.0) 0.905 0.0% (0) 0.0% (0)
ASDAS-CRP 1.6 ± 1.0 (0.0, 5.2) NA NA 0.0% (0) 0.0% (0)
  1. ODI Oswestry Disability Index, HADS Hospital Anxiety and Depression Scale, EQ-5D EuroQol 5-dimension, VAS visual analogue scale, EQ-5D-5 L EuroQol 5-dimension 5-level questionnaire, BASFI Bath Ankylosing Spondylitis Functional Index, BASMI Bath Ankylosing Spondylitis Metrology Index, SF-36 Short Form 36-item questionnaire, PCS Physical Component Score, MCS Mental Component Score, BASDAI Bath Ankylosing Spondylitis Disease Activity Index, ASDAS-CRP Ankylosing Spondylitis Disease Activity Score (C-reactive protein)
  2. Notes: For assessment of function, we use the BASFI score and a higher score means a higher level of functional impairment. For BASMI, it is a reflection of spinal mobility and a higher BASMI reflects a decreased spinal mobility and more established damage