Table 4

Baseline distribution and responsiveness of Canada-Denmark spine inflammation and structural scores compared with SPARCC and BASDAI

Measurement instrument	Observed range	Mean (SD)	Median (IQR)	GRI at week 6	SRM at week 6	SRM at week 24	SRM at week 48
Number of patients analysed	49	49	49	47	47	42	39
Canada-Denmark spine total inflammation score (range 0–582)	0–54	8.8 (12)	4 (1–12)	1.88	0.46	0.57	0.55
Vertebral body subscore (range 0–456)	0–48	8.2 (11)	4 (1–12)	1.99	0.47	0.57	0.55
Anterior corner subscore	0–23	3.6 (5.0)	2 (1–5)	1.64	0.40	0.57	0.59
Posterior corner subscore	0–12	1.4 (2.5)	0 (0–2)	2.56	0.33	0.46	0.45
Non-corner subscore	0–12	1.2 (2.8)	0 (0–0)	0.35	0.30	0.34	0.27
Lateral corner subscore	0–16	2.0 (3.2)	1 (0–3)	1.08	0.45	0.48	0.49
Posterior elements subscore (range 0–126)	0–10	0.6 (1.7)	0 (0–0)	0.84	0.18	0.37	0.35
Canada-Denmark spine erosion score (range 0–320)	0–7	0.7 (1.4)	0 (0–1)	0.20	0.00	0.21	0.19
Fat Spondyloarthritis Spine Score (range 0–456)	0–39	5.5 (8.8)	2 (0–7)	1.25	0.21	0.38	0.38
Canada-Denmark spine new bone formation score (range 0–460)	0–123	7.5 (20)	0 (0–3)	0.22	0.37	0.51	0.48
SPARCC MRI spine index (23-DVU) (range 0–414)	0–52	9.8 (13)	4 (1–14)	1.67	0.48	0.57	0.55
mSASSS	0–61	7.2 (14)	2 (0–6)	NA	NA	NA	0.35
BASDAI (range 0–10)	4.2–9.8	6.4 (1.3)	6.3 (5.4–7.2)	1.32	0.69	1.64	1.96

Median, range and IQR are for all 49 patients. Responsiveness was assessed by SRM and GRI for all patients who had an MRI scan performed at the follow-up timepoint. MRI scores were the average of the two readers. Lateral corner subscore is the sum of antero-lateral and postero-lateral lesion scores.
BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; DVU, discovertebral unit; GRI, Guyatt’s Responsiveness Index; mSASSS, modified Stoke Ankylosing Spondylitis Spine Score; SPARCC, Spondyloarthritis Research Consortium of Canada; SRM, standardised response mean.