Table 9 Discriminatory ability (OASIS database): standardised mean difference between patients with high and low levels of disease activity on a visual analogue scale as judged by the doctor (physician’s global ⩾4 vs <4)

	Physician global ⩾4/10 (n = 28) Mean (SD)	Physician global <4/10 (n = 128) Mean (SD)	Standardised mean difference
ASDAS A	3.58 (1.08)	2.58 (0.99)	0.99
ASDAS B	2.86 (1.03)	2.04 (0.88)	0.90
ASDAS C	3.45 (1.12)	2.45 (1.04)	0.95
ASDAS D	3.66 (1.02)	2.73 (1.00)	0.93
BASDAI	4.43 (2.15)	3.31 (1.99)	0.55
Ln (CRP+1)	2.98 (1.16)	2.07 (1.00)	0.88
CRP (mg/l)*, median (range)	21.5 (0–124)	6.5 (0–75)
√(ESR)	4.24 (1.93)	3.03 (1.38)	0.81
ESR*, median (range)	16.5 (2–74)	8 (0–54)
Ln (swollen joint count+1)	0.39 (0.59)	0.16 (0.43)	0.50
Swollen joint count*, median (range)	0 (0–6)	0 (0–7)
BASFI	5.22 (2.59)	2.99 (2.46)	0.90
BASDAI question 1 (fatigue)	4.72 (3.03)	4.51 (2.78)	0.07
BASDAI question 2 (back pain)	5.38 (2.81)	4.14 (2.54)	0.48
BASDAI question 3 (peripheral pain/swelling)	3.39 (3.54)	2.01 (2.47)	0.52
BASDAI question 6 (duration of morning stiffness)	4.85 (3.51)	3.50 (3.01)	0.43

*For information purposes, actual values are presented.
ASDAS, Ankylosing Spondylitis Disease Activity Score; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Functional Index; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; OASIS, Outcome in Ankylosing Spondylitis International Study.