Abstract
OBJECTIVE: We aimed to identify clinical and demographic features associated with the interval between psoriasis (PsO) and psoriatic arthritis (PsA). METHODS: We identified patients with PsO and PsA diagnoses from our tertiary care psoriatic disease biorepository: a longitudinal, real-world database including clinical information and patient-reported outcomes. We used a multivariable a zero-inflated negative binomial model to evaluate several clinical and demographic features that may be associated with the time between PsO and PsA onset. RESULTS: A total of 384 patients were included, of whom 52.2% were female. The mean age of PsO onset was 31.5 years. Advanced age at PsO onset was associated with a shorter interval between PsO and PsA. Based on our model, patients with PsO onset at age 42.6 years (upper end of the interquartile range [IQR]) had a 62% shorter expected interval compared with patients with PsO onset at age 18.9 years (lower end of IQR) (P < 0.001) and were more likely to have concurrent (onset within 6 months) diagnoses (odds ratio 4.56; 95% confidence interval 2.9-7.17). Patients with a body mass index (BMI) of 34 compared with a BMI of 26 had a 10% shorter interval between PsO and PsA, which trended toward statistical significance (P = 0.053). CONCLUSION: Our study demonstrated that patients with a diagnosis of PsO at an older age have a shorter interval between PsO and PsA diagnoses and are more likely to have concurrent diagnoses compared with patients with an onset of PsO at a younger age. These results suggest that patients with a later onset of PsO may benefit from earlier PsA screening.