Page 68 - Recognizing axial spondyloarthritis - Janneke de Winter

CHAPTER FOUR
Table 1. Characteristics of the healthy participants, patients with axial SpA with a previous MRI positive for sacroiliitis (positive controls), patients with chronic back pain (negative controls), runners, and women with postpartum back pain*
Healthy Patients with participants axial SpA
Controls with chronic back pain (n = 47)
21 (44.7) 30.7 ± 6.5
0 (0)
0 (0)
12.8 ± 7.8
26 (55.3) 20 (42.6) NA
0 (0)
Runners (n = 24)
12 (50.0) 34.3 ± 7.7
0 (0)
NA NA
NA NA NA NA
Women with postpartum back pain (n = 7)
0 (0)
30.1 ± 7.2
0 (0)
NA NA
NA NA NA NA
Men
Age, mean ± SD years
Axial SpA diagnosis
HLA–B27 positive
Duration of back pain, mean ± SD months
Inflammatory back pain
Alternating buttock pain
ASAS axial SpA criteria
Modified New York criteria
(n = 47)
21 (44.7) 30.9 ± 6.5
0 (0)
NA NA
NA NA NA NA
(n = 47)
21 (44.7) 31.5 ± 6.9
47 (100)
35 (74.5) 13.4 ± 7.4
35 (74.5) 40 (85.1) 47 (100) 13 (29.5)
* Except where indicated otherwise, values are the number (%). SpA spondyloarthritis; MRI magnetic resonance imaging; NA not applicable; ASAS Assessment of SpondyloArthritis international Society.
SPARCC scores
Figure 1 shows the individual and mean SPARCC scores for the different patient categories. The mean ± SD SPARCC score was 1.7 2.4 for the 47 healthy participants, 20.9 ± 13.7 for the 47 positive axial SpA controls, and 0.8 ± 1.4 for the 47 non-SpA back pain controls. The mean ± SD SPARCC score was 0.8 ± 1.1 for the runners and 4.5 ± 6.3 for the 7 women with postpartum back pain.
At a SPARCC cutoff score of ≥2, 12 (25.5%) of the 47 healthy volunteers, 46 (97.9%) of the 47 positive axial SpA controls, 5 (10.6%) of the 47 non-SpA back pain controls, 4 (16.7%) of the 24 runners, and 4 (57.1%) of the 7 women with postpartum back pain were considered to have sacroiliitis on MRI. At a SPARCC cutoff score of ≥5, 4 (8.5%) of the 47 healthy volunteers, 41 (87.2%) of the 47 positive patients with axial SpA, 1 (2.1%) of the 47 patients with chronic back pain, 0 (0%) of the 24 runners, and 2 (28.6%) of the 7 women with postpartum back pain were considered to have sacroiliitis on MRI.
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