Background Psoriatic Arthritis (PsA) affects up to 30% of people with psoriasis1. While Tumor Necrosis Factor inhibitors (TNFi) are effective agents for PsA, the relationship between early treatment and patient reported outcomes in a real world setting has not been reported previously.
Objectives To assess whether timely treatment with TNFi leads to better improvement in quality of life outcomes than delayed treatment.
Methods This was a retrospective analysis of patients with PsA and/or Psoriasis (PsO) using TNFi with or without methotrexate, and who had a minimum of 2 visits at the Center of Excellence for Psoriasis and Psoriatic Arthritis at our university. Detailed demographic and clinical characteristics of this cohort have been published previously2. Demographics, quality of life measures (e.g. Routine Assessment of Patient Index Data – RAPID3, Psoriasis Quality of Life – PQoL12, Short Form 12 – SF-12), and clinical data (percent of body surface area involved with PsO – BSA%) were collected from patient-reported questionnaires and electronic medical records. Only those patients who had a chronological overlap of treatment exposure and QoL measures such as RAPID3, BSA, SF12 and PQOL were included. To ascertain treatment effects, a mixed-effects model was fitted to estimate the trend of each QoL outcome of a patient separately. Then, for all estimated trends of an outcome, a linear regression model was employed to explore the association between the magnitude of estimated trends and timeliness of TNFi treatments.
Results The quality of life measures were not affected by how early after the disease onset TNFi treatment was started (in other words, no statistically significant associations between the effectiveness of TNFi treatment and disease duration) for RAPID3 (p=0.285), SF-12 (p=0.674), or BSA (p=0.078). For PQoL, there was a significant association between the trend of treatment effects and timeliness of treatment. A day of delay into treatment was resulted in a reduction of 4.4x10-4/day in the trend of PQoL scores (p=0.007).
Conclusions In this sample of PsA & PsO patients, timing of starting TNFi in patients with PsA had significant impact on improvements in the PQoL but not other quality of life measures such as RAPID3, SF-12 and BSA. A relatively short treatment history might have led to the negative correlations.
McLaughlin M, et.al. Early treatment of psoriatic arthritis improves prognosis. Practitioner 2014 258 (1777) 21–24.
Truong B et.al. Demographics, clinical disease characteristics and quality of life in a large cohost of psoriasis patients with and without psoriatic arthritis. Clin, Cosm and Inv Dermatology 2015: 8: 563–569.
Disclosure of Interest None declared