Table 1.

Baseline patient demographics and characteristics. All values were calculated based on available data and are presented as mean ± SD or n (%).

Characteristics*Overall, n = 1530With Axial Involvement, n = 192Without Axial Involvement, n = 1338p
Age, yrs53.9 ± 13.250.4 ± 13.654.4 ± 13.1< 0.001
Female786 (51.9)102 (54.0)684 (51.6)0.55
Race0.26
  White1397 (94.5)170 (93.9)1227 (94.6)
  Asian24 (1.6)3 (1.6)21 (1.6)
  Black7 (0.4)0 (0.0)7 (0.5)
  Pacific Islander20 (1.3)1 (0.5)19 (1.5)
  Mixed race19 (1.3)6 (3.3)13 (1.0)
  Native American1 (0.1)0 (0.0)1 (0.1)
  Other10 (0.7)1 (0.5)9 (0.7)
BMI, kg/m231.4 ± 7.220.7 ± 7.131.6 ± 7.30.12
BMI (in kg/m2) classifications0.57
  Normal/underweight, < 25.0239 (16.5)33 (18.4)206 (16.2)
  Overweight, 25.0 to < 30.0445 (30.8)58 (32.4)387 (30.5)
  Obese, ≥ 30.0763 (52.7)88 (49.2)675 (53.2)
Disease duration, yrs11.5 ± 10.012.1 ± 10.911.4 ± 9.80.38
HLA-B27
  Patients with available HLA-B27 test result (reported on laboratory form)340 (22.2)84 (43.7)256 (19.1)
    Positive test result (among patients with available test results)62 (18.2)20 (23.8)42 (16.4)0.13
  HLA-B27+, physician-reported78 (5.1)27 (14.1)51 (3.8)< 0.001
History of comorbidities
  Cardiovascular disease756 (49.4)93 (48.4)663 (49.6)0.77
  Depression213 (13.9)44 (22.9)169 (12.6)< 0.001
  Diabetes mellitus206 (13.5)26 (13.5)180 (13.5)0.97
  Any cancer106 (6.9)14 (7.3)92 (6.9)0.83
  Serious infections§77 (5.0)14 (7.3)63 (4.7)0.13
Prior medication use
  Biologics938 (61.3)140 (72.9)798 (59.6)< 0.001
  csDMARD1060 (69.3)135 (70.3)925 (69.1)0.74
  Prednisone186 (12.2)19 (9.9)167 (12.5)0.31
Current biologic use0.006
  None677 (44.2)65 (33.9)612 (45.7)
  Monotherapy468 (30.6)77 (40.1)391 (29.2)
  Concomitant MTX only335 (21.9)41 (21.4)294 (22.0)
  Concomitant MTX + other csDMARD15 (1.0)3 (1.6)12 (0.9)
  Concomitant other csDMARD only35 (2.3)6 (3.1)29 (2.2)
Current prednisone use103 (6.7)9 (4.7)94 (7.0)0.227
  • * All variables had < 20% missing data.

  • Combined histories of myocardial infarction, acute coronary syndrome, coronary artery disease, congestive heart failure, hypertension, hyperlipidemia, peripheral artery disease, cardiac revascularization procedure, ventricular arrhythmia, cardiac arrest, unstable angina, stroke, transient ischemic attack, pulmonary embolism, carotid artery disease, deep vein thrombosis, or other cardiovascular event.

  • Excludes nonmelanoma of the skin.

  • § Includes those infections that lead to hospitalization or intravenous antibiotics: joint/bursa, cellulitis, sinusitis, diverticulitis, sepsis, pneumonia bronchitis, gastroenteritis, meningitis, urinary tract infection, upper respiratory tract infection, or infection of other specified site. BMI: body mass index; csDMARD: conventional synthetic disease-modifying antirheumatic drug; MTX: methotrexate.