Table 1

Baseline characteristics and demographics associated with the incidence of OS in patients with SpA (SpA cohort) and a matched cohort from the general population (non-SpA cohort) by type of OS.

SpA cohortNon-SpA cohort
OS (all)THATKAULAArthrodesisSpinal surgeryOS (all)THATKAULAArthrodesisSpinal surgery
N (% of OS)5400 (100)2261 (41.9)1115 (20.6)345 (6.4)172 (3.2)1525 (28.2)3540 (100)1220 (34.5)1209 (34.2)482 (13.6)75 (2.1)561 (15.8)
Mean age (SD)58.97 (13.50)57.76 (14.1164.83 (10.28)54.89 (12.59)52.07 (12.31)58.15 (13.62)63.67 (12.58)67.28 812.35)68.38 (7.85)55.59 (11.85)50.76 (12.24)54.3 (12.42)
Mean Charlson index (SD)0.45 (0.94)0.37 (0.80)0.38 (0.71)0.32 (0.65)0.23 (0.48)0.68 (1.29)0.33 (0.89)0.45 (1.05)0.28 (0.61)0.17 (0.50)0.19 (0.53)0.38 (1.24)
Average length of stay in days (SD)16.31 (25.43)11.53 (11.73)9.89 (11.30)4.29 (16.11)4.74 (9.33)32.05 (39.6)9.12 (11.12)11.3 (12.07)8.4 (6.50)3.08 (4.29)4.03 (5.77)12.23 (20.01)
Male n (%)3439 (63.7)1704 (75.4)562 (50.4)159 (46.1)82 (47.7)940 (61.6)1866 (52.7)712 (58.4)480 (39.7)257 (53.3)44 (58.7)375 (66.8)
Death during admission, n (%)69 (1.3)15 (0.7)2 (0.2)0 (0)0 (0)52 (3.4)17 (0.5)13 (1.1)0 (0)0 (0)0 (0)4 (0.7)
Diabetes mellitus (%)601 (11.1)184 (8.1)156 (14)38 (11)13 (7.6)212 (13.9)356 (10.1)133 (10.9)147 (12.2)29 (6)3 (4)45 (8)
Hypertension (%)1695 (31.4)642 (28.4)510 (45.7)90 (26.1)22 (12.8)437 (28.7)1169 (33)412 (33.8)539 (44.6)87 (18)9 (12)123 (21.9)
Smoking (%)326 (6.0)118 (5.2)32 (2.9)22 (6.4)12 (7)144 (9.4)149 (4.2)43 (3.5)26 (2.2)20 (4.1)8 (10.7)53 (9.4)
Deep vein thrombosis (%)6 (0.1)1 (0.1)2 (0.2)0 (0)0 (0)3 (0.2)2 (0.1)1 (0.1)0 (0)0 (0)0 (0)1 (0.2)
Dementia (%)15 (0.3)13 (0.6)0 (0)0 (0)0 (0)2 (0.1)15 (0.4)13 (1.1)2 (0.2)0 (0)0 (0)0 (0)
Depression (%)280 (5.2)87 (3.8)73 (6.5)30 (8.7)4 (2.3)86 (5.6)167 (4.7)47 (3.9)64 (5.3)19 (3.9)4 (5.3)35 (6.2)
  • AS, ankylosing spondylitis; OS, orthopaedic surgery; PsA, psoriatic arthritis; SpA-IBD, spondyloarthritis associated with inflammatory bowel disease; THA, total hip arthroplasty; TKA, total knee arthroplasty; ULA, upper limb arthroplasty.