Table 2 Basal characteristics and clinical features of patients with AS and of normal controls.

Sex, M:F (%)

88:7 (92.6:7.4)

76:54 (58.5:41.5)

Age (mean ± SD)

33.4 ± 9.4

66.3 ± 5.8

Disease subgroup, n

   Idiopathic AS

83

   IBD

3

   Reactive arthritis

2

   Psoriatic arthritis

1

   JAS

6

Clinical features

   Age on initial symptom, years (mean ± SD)

23.1 ± 7.6

   Disease duration, months (mean ± SD)

25.9 ± 8.5

   Delayed diagnosis, months (mean ± SD)

32.1 ± 38.2

   HLA B27⁺ (n = 84) (%)

74 (88.1)

Complications, n (%)

   Uveitis

8 (8.4)

   Peripheral joint involvement

28 (29.4)

   Total hip replacement

13 (13.5)

   IgA nephropathy

0 (0)

   Heart conduction abnormality

0 (0)

   Pneumonitis

0 (0)

   Cauda equina syndrome

3 (3.1)