Table 1.

Demographic and Clinical Characteristics of Study Group

Variables		n/mean	% or Standard Deviation (SD)
Number of patients with axSpA/AS		354	-
Number of observations		2733	-
Mean age at enrollment		55.11	12.726 (SD)
Mean disease duration at enrollment		17.36	14.905 (SD)
Self-identified gender	Male Female Unknown/did not disclose	327 21 6	92.4% 5.9% 1.7%
Race	Caucasian African American Hispanic American Indian/Pacific Islander Asian Other Unknown/did not disclose	257 45 30 5 5 1 11	74.9% 13.1% 8.8% 1.5% 1.5% 0.3% 3.1%
HLAB27 status	Positive Negative Unknown	254 43 57	71.8% 12.1% 16.1%
Cigarette smoking status	Current Former Never Unknown	91 135 96 32	27.1% 38.1% 25.7% 9.0%
Alcohol use	Current Former Never Unknown	135 54 40 125	38.1% 15.3% 11.3% 35.3%
Mean BASDAI		5.35 (mean)	1.879 (SD)
TNFi use	All Adalimumab Etanercept Certolizumab Golimumab Infliximab	244 145 99 15 30 55	68.9% 41.0% 28.0% 4.2% 8.5% 15.5%
Number of observations	Absolute neutrophils Platelets Lymphocytes ESR CRP NLR PLR	10,191 8,363 10,296 5,558 4,990 10,189 6,997	- - - - - - -
Mean laboratory values prior to TNFi use	NLR PLR ESR CRP	2.93 134.33 22.74 1.74	3.029(SD) 97.18(SD) 22.36(SD) 2.81(SD)

axSpA, axial spondyloarthritis; AS, ankylosing spondylitis, BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; TNFi, tumor necrosis factor inhibitor; ESR, erythrocyte sedimentation rate; CRP, C-reactive protein; NLR, neutrophil/lymphocyte ratio; PLR, platelet/lymphocyte ratio