Table 3.

Adjusted difference between HLA‐B27+ and HLA‐B27− treatment initiators in PsA disease outcomes (mean change from baseline to 6 months)

Disease characteristic	β Estimate for HLA‐B27+ status (95% CI)	P value
BASDAI (0‐10)	0.10 (−0.56 to 0.75)	0.78
BASDAI Question 2: spine pain	1.52 (−6.30 to 9.34)	0.70
Modified BASDAI score (0‐10)	0.11 (−0.56 to 0.78)	0.75
Tender joint count (0‐68 joints)	−0.19 (−2.80 to 2.42)	0.88
Swollen joint count (0‐66 joints)	−0.15 (−1.48 to 1.19)	0.83
Physician Global Assessment of PsA (0‐100 mm VAS)	1.73 (−7.27 to 10.73)	0.71
Patient‐reported pain (0‐100 mm VAS)	2.95 (−5.70 to 11.60)	0.50
Patient‐reported spine pain (0‐100 mm VAS)	−0.07 (−8.47 to 8.33)	0.99
Patient‐reported nocturnal spine pain (0‐100 mm VAS)	2.98 (−6.56 to 12.53)	0.54
HAQ‐DI (0‐3)	−0.01 (−0.17 to 0.15)	0.90
HAQ‐S (0‐3)	0.00 (−0.16 to 0.16)	>0.99
BSA (%)	−1.30 (−3.18 to 0.57)	0.17
CDAI (0‐76)	0.18 (−3.69 to 4.05)	0.93

Abbreviations: BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; bDMARD, biologic disease‐modifying antirheumatic drug; BSA, body surface area of psoriasis; CDAI, Clinical Disease Activity Index; CI, confidence interval; HAQ‐DI, Health Assessment Questionnaire‐Disability Index; HAQ‐S, Health Assessment Questionnaire for the Spondyloarthropathies; HLA, human leukocyte antigen; PsA, psoriatic arthritis; tsDMARD, targeted synthetic disease‐modifying antirheumatic drug; VAS, visual analog scale.

Note: Linear regression model estimates were adjusted for baseline value and other potential risk factors (age at initiation, insurance, alcohol use, history of cardiovascular disease, prior conventional synthetic DMARD use, prior bDMARD use, and prior tsDMARD use). The HLA‐B27− group is the reference group for this comparison.