Fig. 1.

Inflammatory measures in CSA patients (A) with and without MS and (B) associations for different MS cut-offs

CRP: CRP increased if ≥5 mg/l; MS+: presence of MS with a duration ≥60 min; +: presence of an MRI feature.

Any subclinical inflammation: presence of one or more inflammatory features (osteitis, synovitis and tenosynovitis).

*Statistically significant associations (CI not including 1). (A) Increased CRP levels were more often found in CSA patients with MS (31% vs 19%). Likewise, subclinical synovitis was more often present in CSA patients with MS compared with patients without MS (34% vs 21%). Also, subclinical tenosynovitis was more frequently present in patients with MS (36% vs 26%). (B) Evaluating the univariable association for different MS durations (≥30, ≥60, ≥120 min) showed a ‘dose–response’ relation, with a step-wise increase for the OR for any subclinical MRI inflammation and subclinical tenosynovitis. For subclinical synovitis and CRP, an increase for ≥60 min compared with ≥30 min was observed, but no further increase for ≥120 min. Vertical error bars represent the 95% CI.