AxSpA | Non-axSpA | |||||
Baseline | 2 years | P value (within group*) | Baseline | 2 years | P value (within group*) | |
Overall back pain intensity‡, N | 250 | 94 | ||||
Mean (SD) | 4.0 (2.4) | 2.6 (2.3) | <0.001† | 5.5 (2.2) | 3.9 (2.6) | <0.001† |
Change over time, mean (SD) | −1.4 (2.5) | −1.6 (2.4) | ||||
Present (score >2), n (%) | 169 (68) | 107 (43) | 85 (90) | 63 (67) | ||
Back pain at night intensity‡, N | 248 | 94 | ||||
Mean (SD) | 3.6 (2.9) | 2.2 (2.5) | <0.001† | 4.6 (2.7) | 3.6 (2.8) | 0.001† |
Change over time, mean (SD) | −1.4 (2.9) | −1.0 (2.7) | ||||
Present (score >2), n (%) | 147 (59) | 82 (33) | 71 (76) | 56 (60) | ||
Morning stiffness intensity§, N | 261 | 106 | ||||
Mean (SD) | 4.7 (2.9) | 3.1 (2.6) | <0.001† | 6.0 (2.8) | 4.0 (3.0) | <0.001† |
Change over time, mean (SD) | −1.6 (3.2) | −1.9 (2.9) | ||||
Present (score >2), n (%) | 186 (71) | 126 (48) | 89 (84) | 66 (62) | ||
Morning stiffness duration§, N | 260 | 107 | ||||
Mean (SD) | 3.6 (2.8) | 2.3 (2.4) | <0.001† | 4.6 (2.9) | 3.1 (2.9) | <0.001† |
Change over time, mean (SD) | −1.2 (3.0) | −1.5 (3.1) | ||||
Present (score >2), n (%) | 159 (61) | 97 (37) | 82 (77) | 51 (48) | ||
Overall morning stiffness§, N | 260 | 106 | ||||
Mean (SD) | 4.1 (2.6) | 2.7 (2.3) | <0.001† | 5.3 (2.5) | 3.6 (2.8) | <0.001† |
Change over time, mean (SD) | −1.4 (2.8) | −1.7 (2.6) | ||||
Present (score >2), n (%) | 184 (71) | 128 (49) | 92 (87) | 68 (64) |
*Comparison of outcomes at baseline and 2 years within groups.
†Statistical significance.
‡<20% missing data.
§<15% missing data.
axSpA, axial spondyloarthritis.