A Real-World Analysis of Weather Variation on Disease Activity and Patient-Reported Outcomes in Psoriatic Arthritis.

Objective: Patients with inflammatory articular diseases, such as psoriatic arthritis (PsA), report weather changes in their symptoms. Our objective was to investigate the correlation between weather variation, disease activity (DA), and patient-reported outcomes (PROs) in patients with PsA.

Methods: Hourly measurements of temperature, relative humidity, and pressure were obtained from 2015 to 2020 in Montreal (through Environment Canada) and were matched with DA and PROs of patients with PsA enrolled in Rhumadata. The differences in mean DA and PROs were examined between winter and summer. Pearson correlation coefficients were calculated between clinical profile and weather measurements.

Results: Among patients with PsA, 2665 PROs were collected for a total of 858 patients. The Clinical Disease Activity Index ( = 0.001) and Simplified Disease Activity Index ( < 0.001) were lower in winter. In summer, positive correlations were found between humidity and symptoms (using patient global assessment, fatigue, pain, C-reactive protein, Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Functional Index), whereas negative correlations between temperature and Health Assessment Questionnaire-Disability Index were reported. In winter, positive correlations were observed between temperature, fatigue, and pain.

Conclusion: This is the first study to investigate weather variations through subjective and objective PROs matched with patients with PsA. Statistically significant differences in clinical profile were evident between winter and summer, as well as in their correlation with weather measurements. However, these distinctions lack clinical significance, suggesting a small impact on patients with PsA.