Weiyu Ye1, Simon Hackett1, Claire Vandevelde1, Sarah Twigg1, Philip S Helliwell1, Laura C Coates1. 1. WY is a National Institute for Health Research (NIHR) Academic Clinical Fellow. LCC is an NIHR Clinician Scientist and Senior Clinical Research Fellow funded by an NIHR Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. We acknowledge the support of the NIHR Clinical Research Network. 1W. Ye, NIHR Academic Clinical Fellow, MB BChir, Oxford University Clinical Academic Graduate School, John Radcliffe Hospital, Oxford; 2S. Hackett, Academic Foundation Doctor, PhD, L.C. Coates, NIHR Clinician Scientist and Senior Clinical Research Fellow, PhD, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Science, University of Oxford, The Botnar Research Centre, Oxford; 3C. Vandevelde, Consultant Rheumatologist and Honorary Senior Lecturer, MD, NIHR Leeds Biomedical Research Centre, Leeds Teaching Hospitals NHS Trust, and Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, Leeds; 4S. Twigg, Consultant Rheumatologist, MD, Bradford Teaching Hospitals NHS Foundation Trust, St. Lukes Hospital, Bradford; 5P.S. Helliwell, Professor of Clinical Rheumatology, PhD, Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, Chapel Allerton Hospital, Leeds, UK. Address correspondence to Dr. W. Ye, Oxford University Clinical Academic Graduate School, Room 3A31, The Cairns Library IT Corridor, Level 3, John Radcliffe Hospital, Oxford, OX3 9DU, UK. Email: christina.ye@conted.ox.ac.uk. Accepted for publication November 10, 2020.
Abstract
OBJECTIVE: Patient self-report scales are invaluable in psoriatic arthritis (PsA), as they allow physicians to rapidly assess patient perspectives of disease activity. We aimed to assess the agreement of the visual analog scale (VAS), a 100-mm horizontal line, and the numerical rating scale (NRS), a 21-point scale ranging from 0 to 10 in increments of 0.5, in patients with PsA. METHODS: Data were collected prospectively across 3 UK hospital trusts from 2018 to 2019. All patients completed the VAS and NRS for pain, arthritis, skin psoriasis (PsO), and global disease activity. A subset completed an identical pack 1 week later. Demographic and clinical data were also collected. Agreement was assessed using medians and the Bland-Altman method. Intraclass correlation coefficients (ICCs) were used to assess test-retest reliability. Spearman rank correlation coefficients were used to assess dependency between scale scores and clinical variables. RESULTS: Two hundred ten patients completed the study; 1 withdrew consent. Thus, 209 were analyzed. For pain, arthritis, skin PsO, and global disease activity, the difference between the VAS and NRS lay mostly within 1.96 SD of the mean, suggesting reasonable agreement between the 2 scales. Among the patients, 64.1% preferred the NRS. The ICCs demonstrated excellent test-retest reliability for both VAS and NRS. Higher VAS and NRS scores were associated with increased tender/swollen joint count, poorer functional status, and greater life impact. CONCLUSION: The VAS and NRS show reasonable agreement in key patient-reported outcomes in PsA. Results from both scales are correlated with disease severity and life impact.
OBJECTIVE:Patient self-report scales are invaluable in psoriatic arthritis (PsA), as they allow physicians to rapidly assess patient perspectives of disease activity. We aimed to assess the agreement of the visual analog scale (VAS), a 100-mm horizontal line, and the numerical rating scale (NRS), a 21-point scale ranging from 0 to 10 in increments of 0.5, in patients with PsA. METHODS: Data were collected prospectively across 3 UK hospital trusts from 2018 to 2019. All patients completed the VAS and NRS for pain, arthritis, skin psoriasis (PsO), and global disease activity. A subset completed an identical pack 1 week later. Demographic and clinical data were also collected. Agreement was assessed using medians and the Bland-Altman method. Intraclass correlation coefficients (ICCs) were used to assess test-retest reliability. Spearman rank correlation coefficients were used to assess dependency between scale scores and clinical variables. RESULTS: Two hundred ten patients completed the study; 1 withdrew consent. Thus, 209 were analyzed. For pain, arthritis, skin PsO, and global disease activity, the difference between the VAS and NRS lay mostly within 1.96 SD of the mean, suggesting reasonable agreement between the 2 scales. Among the patients, 64.1% preferred the NRS. The ICCs demonstrated excellent test-retest reliability for both VAS and NRS. Higher VAS and NRS scores were associated with increased tender/swollen joint count, poorer functional status, and greater life impact. CONCLUSION: The VAS and NRS show reasonable agreement in key patient-reported outcomes in PsA. Results from both scales are correlated with disease severity and life impact.