Skin Involvement in Psoriatic Arthritis Worsens Overall Disease Activity, Patient-Reported Outcomes, and Increases Healthcare Resource Utilization: An Observational, Cross-Sectional Study

Abstract

Introduction: Psoriatic arthritis (PsA) is an inflammatory arthropathy that exhibits heterogeneity in clinical presentation and severity of skin and joint symptoms. This heterogeneity results in an incomplete understanding of the relationship between the skin and joint components of PsA, and their relative impact on PsA disease activity and patient-reported outcomes. The objective of the study was to Investigate the clinical presentation of joint and active skin symptom involvement and the associated impact on physician- and patient-reported outcomes [patient global assessment (PtGA), health-related quality of life (HRQoL), and physical function), and healthcare resource burden in patients with PsA.

Methods: This was a retrospective analysis of the Adelphi 2015 PsA Disease Specific Programme, a real-world, cross-sectional survey of rheumatologists and their consulting PsA patients from the USA and Europe (France, Germany, Italy, Spain, and UK). The sample included data collected during the fourth quarter of 2015, on 1201 patients from 410 rheumatologists. Physician-reported joint and active skin symptom involvement were investigated for associations with clinical outcomes, patient/physician-reported outcomes, and healthcare resource utilization (HCRU).

Results: The majority of patients with PsA with documented skin involvement had both joint and active skin involvement (80.9%, n_joint+skin = 515, n_{joint only} = 122, n_overall = 637). Patients with skin involvement possessed a more severe global clinical profile, and the PsA clinical symptom severity profile positively correlated with skin severity. Physician global assessment scores were not significantly different in patients with joint-only involvement vs. joint with active skin involvement. Patients with skin involvement in PsA possessed significantly worse PtGA scores and increased HCRU.

Conclusion: Patients with PsA involving both joint and active skin symptoms exhibit a more severe overall disease state, worse patient-reported outcomes, and increased HCRU relative to patients with joint-only involvement in PsA. These results indicate that treating skin involvement should be considered along with treating joint involvement in patients with PsA.

Funding: Eli Lilly and Company.

Keywords: Healthcare resource utilization; Joint; Patient-reported outcomes; Psoriatic arthritis; Skin.

Fig. 1

Profile of psoriatic arthritis disease in patients when stratified according to joint involvement without active skin symptoms (joint only, n = 122) and joint involvement with active skin symptoms (skin and joint, n = 515) measured by a number of affected joints, b current level of pain, c number of psoriatic arthritis symptoms, d number of other current symptoms. *p < 0.0001, p values from Student’s t test. SD standard deviation

Fig. 2

Profile of psoriatic arthritis disease in patients according to physician classification of current skin severity [none (n = 170), mild (n = 538), moderate (n = 340), severe (n = 55)] as measured by a total number of affected joints, b current level of pain, c number of psoriatic arthritis symptoms, and the d number of other current symptoms. *p < 0.01, **p < 0.0001 both calculated from Spearman’s correlation. SD standard deviation

Fig. 3

Disease state, health-related quality of life, and physical function as measured by a patient global assessment, b physician global assessment, c EuroQoL (EQ)-5D, and d health assessment questionnaire disability index (HAQ-DI) in PsA patients when stratified according to joint involvement without active skin symptoms (joint only) and joint involvement with active skin symptoms (skin and joint). Some measures were missing for some patients; in these instances, the numbers of missing patients and included patients are displayed in the figure. *p < 0.05 vs. joint-only subgroup. p values from Student’s t test. n number of patients, SD standard deviation