The Impact of Comorbidity on Patient-Reported Outcomes in Psoriatic Arthritis: A Systematic Literature Review.

A systematic literature review was conducted with the aim to analyse the impact of comorbidity on patient-reported outcomes (PROs) in patients with psoriatic arthritis (PsA). A sensitive search strategy of the Medline, Embase and the Cochrane Library (up to March 2019) was applied to retrieve studies for inclusion in this systematic literature review. Abstracts of the ACR and EULAR scientific meetings were also searched. The selection criteria were: (1) patients with PsA (population) with a comorbidity (intervention) and (2) report of any impact of the comorbidity on PROs. Systematic literature reviews, randomized controlled trials and observational were included in this systematic literature review. Two of the authors selected the articles and collected the data. Eighteen articles were included in this systematic literature review, with most being cross-sectional studies that included more than 9000 patients with PsA. Some studies analysed the impact of an individual comorbidity, such as fibromyalgia (FM), and in others the analysis was according to the number of comorbidities. The most frequently analysed PROs were function, quality of life and fatigue. Analysis of the studies included in the review showed that patients with a higher number of comorbidities and/or more severe comorbidities reported worse impacts of their disease on function, patient's global assessment (PGA), pain, fatigue, work disability and quality of life. Specifically, FM had a negative impact on the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), function, quality of sleep and quality of life; anxiety and depression had a negative impact on function and fatigue; metabolic syndrome had a negative impact on BASDAI, function, PGA and quality of life; obesity had a negative impact on function and pain; smoking (current and ex-smokers) had a negative impact on pain, function, fatigue, quality of life and overall health; alcohol intake had a negative impact on pain, function, fatigue, quality of life and overall health. The prevalence and impact of medical comorbidity on PROs are very high in patients with PsA.