Time-dependent univariate Cox proportional regression for the development of peripheral disease among PsA patients who presented with isolated axial disease, adjusted by sex and age at diagnosis of PsA (N=32)
| Variable | HR | 95% CI | P value |
| Sex (male) | |||
| Age at diagnosis of PsA in years | |||
| Sacroiliitis grade* | 1.302 | (0.497 to 3.406) | 0.591 |
| Enthesitis | 0.000 | (0.000 to ∞) | 0.998 |
| Elevated ESR | 1.292 | (0.454 to 3.672) | 0.631 |
| Nail lesion | 0.984 | (0.388 to 2.500) | 0.974 |
| PASI | 1.039 | (0.984 to 1.098) | 0.167 |
| Uveitis | 2.752 | (0.883 to 8.572) | 0.081 |
| HLA-B*27 | 7.544 | (1.792 to 31.769) | 0.006 |
| NSAIDS | 0.924 | (0.322 to 2.655) | 0.884 |
| DMARDS | 1.454 | (0.570 to 3.710) | 0.434 |
| Biologics | 1.086 | (0.335 to 3.515) | 0.891 |
*The sacroiliac joint with the highest grade was used preferentially for analysis.
DMARD, disease-modifying antirheumatic drug; ESR, erythrocyte sedimentation rate; HAQ, Health Assessment Questionnaire; NSAID, nonsteroidal anti-inflammatory drug; PASI, psoriasis area and severity index; PsA, psoriatic arthritis.