Table 1. Demographic and disease characteristics at baseline of patients with ankylosing spondylitis (AS) and a history of anterior uveitis (AU).

	All patients (n = 1250)	History of AU* (n = 274)	Recent history of AU† (n = 106)	Symptomatic AU at baseline (n = 28)	Chronic AU‡ (n = 43)
Chronic uveitis, %	3	16	25	36	100
Male, %	71	70	74	82	72
Age, years, mean (SD)	43.6 (11.4)	45.6 (10.6)	44.0 (10.0)	46.1 (13.0)	44.4 (9.9)
AS duration, years, mean (SD)	11.0 (9.8)	14.8 (10.6)	13.4 (9.3)	14.8 (8.4)	15.1 (9.2)
Advanced AS§, %	27	31	31	41	26
Time since onset of uveitis, years, mean (SD)	NA	9.9 (8.9)	6.6 (8.8)	7.4 (8.4)	9.4 (7.9)
HLA-B27 positive, %	82	91	89	82	90
BASDAI, mean (SD)	6.3 (1.4)	6.3 (1.4)	6.5 (1.4)	6.2 (1.7)	6.6 (1.5)
BASFI, mean (SD)	5.4 (2.2)	5.2 (2.3)	5.0 (2.5)	5.0 (2.8)	5.2 (2.5)
CRP, mg/dl, mean (SD)	2.0 (2.4)	2.4 (2.8)	2.8 (3.6)	4.1 (4.9)	2.6 (3.0)
Treatment with DMARDs, %	26	28	19	32	26
Treatment with sulfasalazine, %	12	13	9	25	12
Oral NSAIDs, %	74	79	78	71	84
Oral glucocorticoids, %	14	13	9	14	16
Previous etanercept and/or infliximab treatment, %	26	23	26	29	35

*History of AU, history of at least one AU flare anytime. †Recent history of AU, history of at least one AU flare in the past year. ‡Chronic uveitis refers to persistent AU flares of at least 3-month duration and with relapse within less than 3 months according to the Standardization of Uveitis Nomenclature Working Group.⁶ §Advanced AS, radiographically involvement of at least 50% of the spine in >2 segments.²⁸

BASDAI, Bath AS Disease Activity Index; BASFI, Bath AS Functional Index; CRP, C-reactive protein; DMARDs, disease-modifying antirheumatic drugs; NA, not applicable; NSAIDs, non-steroidal anti-inflammatory drugs.