Table 1.
Factors associated with BAS-Ga
| Coefficient (95% CI) |
||
|---|---|---|
| Explanatory variable | Univariable analysis | Multivariable analysis |
| BASDAI Q1 (fatigue, 0–10) | 0.68 (0.65, 0.70) | 0.17 (0.13, 0.22)* |
| BASDAI Q2 (back pain, 0–10) | 0.83 (0.81, 0.85) | 0.51 (0.46, 0.56)* |
| BASDAI Q3 (peripheral joint pain, 0–10) | 0.51 (0.48, 0.54) | 0.08 (0.04, 0.12)* |
| BASDAI Q4 (enthesitis, 0–10) | 0.60 (0.58, 0.62) | 0.03 (−0.01, 0.07) |
| BASDAI Q5 (severity of morning stiffness, 0–10) | 0.66 (0.64, 0.68) | 0.08 (0.03, 0.13)* |
| BASDAI Q6 (duration of morning stiffness, 0–10) | 0.50 (0.47, 0.53) | 0.03 (−0.01, 0.07) |
| SJC28 (0–28) | 0.14 (0.06, 0.23) | 0.01 (−0.11, 0.13) |
| TJC53 (0–159)b | 0.08 (0.07, 0.09) | −0.01 (−0.02, 0.01) |
| MASES (0–39) | 0.15 (0.14, 0.17) | 0.00 (−0.02, 0.02) |
| CRP (mg/l) | 0.04 (0.03, 0.05) | 0.01 (−0.00, 0.01) |
| Any EMM (presence vs absence) | −0.02 (−0.26, 0.22) | −0.05 (−0.21, 0.11) |
| BASFI (0–10) | 0.85 (0.82, 0.88) | 0.14 (0.08, 0.19)* |
| BASMI linear (0–10) | 0.69 (0.59, 0.80) | −0.07 (−0.16, 0.02) |
| mNY grading (0–8) | −0.16 (−0.25, −0.07) | 0.01 (−0.03, 0.06) |
| mSASSS (0–72) | −0.09 (−0.15, −0.03) | −0.01 (−0.04, 0.02) |
Associations of the potential explanatory variables of BAS-G and BAS-G are expressed as regression coefficient (95% CI) in generalized estimating equation models with the potential explanatory variables as independent time-varying variables and BAS-G as the dependent time-varying variable.
Total score of the 53 joints with each joint graded 0–3 (0 = no tenderness, 1 = tenderness, 2 = tenderness + grimace, 3 = tenderness + grimace + withdrawal).
P-value <0.05 (multivariable analysis). BASDAI Q1–6: individual component questions of BASDAI; EMM: extra-musculoskeletal manifestations; MASES: Maastricht Ankylosing Spondylitis Enthesitis Score; mNY grading: modified New York grading; mSASSS: modified Stoke Ankylosing Spondylitis Spine Score; SJC28: swollen joint count in the 28 joints; TJC53: tender joint score in the 53 joints.