Summary of the results of all fitted models evaluating the association of seasons (winter vs summer) with the outcomes while controlling for different covariates
| Covariates* | Outcomes of all fitted models | OR | 95% CI | p Value |
|---|---|---|---|---|
| Season: winter vs summer | BASDAImoderate-severe vs BASDAIminimal-moderate | 0.85 | 0.34 to 2.13 | 0.725 |
| BASDAI as a continuous variable (1 unit increase) | 1.05 | 0.44 to 2.49 | 0.918 | |
| PGAfair-very poor vs PGAgood-very good | 1.39 | 0.99 to 1.94 | 0.056 | |
| PASImild-severe vs PASIremission-minimal | 1.09 | 0.81 to 1.46 | 0.584 | |
| PASI as a continuous variable (1 unit increase) | 2.16 | 0.95 to 4.91 | 0.065 |
↵* All models included the same covariates, namely: season (winter vs summer), age (1-year increase), sex (males vs females), duration of psoriatic arthritis at first visit (1-year increase), calendar time (one decade increase), biologics (yes vs no), disease-modifying antirheumatic drugs (yes vs no), non-steroidal anti-inflammatory drugs (yes vs no) and ultraviolet therapy (yes vs no).
BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; PASI, Psoriasis Area and Severity Index; PGA, patient global assessment.