Table 6.
Baseline factors associated with response at follow-up (stepwise logistic regression models)
| ASAS 20 response |
ASAS 40 response |
ASDAS ≥1.1 reduction |
ASDAS score <2.1 |
||||||
|---|---|---|---|---|---|---|---|---|---|
| (model n = 261) |
(model n = 326) |
(model n = 253) |
(model n = 239) |
||||||
| Participants meeting response criteria (%) |
52% |
33% |
47% |
35% |
|||||
| Baseline variables | OR | (95% CI) | OR | (95% CI) | OR | (95% CI) | OR | (95% CI) | |
| Employment | Full-time | Ref | – | Ref | – | Ref | – | Ref | – |
| Part-time | 0.48 | (0.23, 1.03) | 0.38 | (0.17, 0.84) | 0.39 | (0.15, 1.02) | 0.28 | (0.11, 0.74) | |
| Unpaid/seeking | 1.80 | (0.53, 6.13) | 1.16 | (0.38, 3.53) | 0.23 | (0.04, 1.26) | 0.24 | (0.05, 1.28) | |
| Retired | 0.67 | (0.31, 1.47) | 1.52 | (0.68, 3.43) | 1.08 | (0.37, 3.15) | 0.90 | (0.33, 2.47) | |
| Retired/unemployed due to ill-health | 0.37 | (0.18, 0.76) | 0.26 | (0.11, 0.63) | 0.29 | (0.11, 0.76) | 0.04 | (0.01, 0.34) | |
| Student | Low N. | 0.99 | (0.13, 7.73) | 2.14 | (0.12, 38.22) | 2.69 | (0.26, 27.50) | ||
| BMI | Per unit increase | 0.96 | (0.91, 1.003) | ||||||
| Education | Secondary school | Ref | – | Ref | – | ||||
| Apprenticeship | 1.99 | (0.85, 4.64) | 1.43 | (0.50, 4.08) | |||||
| College | 1.41 | (0.72, 2.75) | 1.01 | (0.43, 2.36) | |||||
| University degree | 2.82 | (1.41, 5.61) | 1.72 | (0.72, 4.10) | |||||
| Further degree | 1.27 | (0.47, 3.41) | 2.62 | (0.83, 8.28) | |||||
| Enthesitis | Yes vs no | 3.85 | (1.33, 11.11) | ||||||
| SF-12-MCS | Per unit increase | 1.05 | (1.02, 1.09) | 1.05 | (1.01, 1.08) | ||||
| ASDAS | Per unit increase | 4.43 | (2.83, 6.94) | ||||||
| Gender | Female vs male | 0.59 | (0.29, 1.20) | ||||||
| Comorbidity count | Per unit increase | 0.64 | (0.45, 0.92) | 0.57 | (0.37, 0.88) | 0.60 | (0.38, 0.95) | ||
| HADs anxiety | Per unit increase | 0.94 | (0.88, 0.99) | ||||||
| Model fit | ROC area under curve (95% CI) | 0.68 (0.61, 0.74) | 0.71 (0.65, 0.77) | 0.85 (0.80, 0.89) | 0.81 (0.75, 0.86) | ||||
| Sensitivity/Specificity (%) | 70.7/56.3 | 32.1/88.5 | 73.3/78.9 | 56.5/81.8 | |||||
| PPV/NPV | 62.7/64.9 | 58.3/72.2 | 75.9/76.6 | 63.2/77.3 | |||||
OR: odds ratio; ref: reference category; ASAS: assessment in ankylosing spondylitis; ASDAS: ankylosing spondylitis disease activity score; SF-12 MCS: short form 12 mental component score; SF-12 PCS: short form 12 physical component score; HADS: hospital anxiety and depression scale; ROC: receiver operating characteristic; PPV: positive predictive value; NPV: negative predictive value.