Comparison of the Utility and Validity of Three Scoring Tools to Measure Skin Involvement in Patients With Juvenile Dermatomyositis.

Raquel Campanilho‐Marques,Kiran Nistala,Natacha Gallot,Katie Arnold,Claire Deakin,Clarissa A Pilkington,Lucy R Wedderburn,Beverley Almeida,Maria De Iorio

doi:10.1002/acr.22867

Abstract

ObjectiveTo compare the abbreviated Cutaneous Assessment Tool (CAT), Disease Activity Score (DAS), and Myositis Intention to Treat Activity Index (MITAX) and correlate them with the physician's 10‐cm skin visual analog scale (VAS) in order to define which tool best assesses skin disease in patients with juvenile dermatomyositis.MethodsA total of 71 patients recruited to the UK Juvenile Dermatomyositis Cohort and Biomarker Study were included and assessed for skin disease using the CAT, DAS, MITAX, and skin VAS. The Childhood Myositis Assessment Scale (CMAS), manual muscle testing of 8 groups (MMT8), muscle enzymes, inflammatory markers, and physician's global VAS were recorded. Relationships were evaluated using Spearman's correlations and predictors with linear regression. Interrater reliability was assessed using intraclass correlation coefficients.ResultsAll 3 tools showed correlation with the physician's global VAS and skin VAS, with DAS skin showing the strongest correlation with skin VAS. DAS skin and CAT activity were inversely correlated with CMAS and MMT8, but these correlations were moderate. No correlations were found between the skin tools and inflammatory markers or muscle enzymes. DAS skin and CAT were the quickest to complete (mean ± SD 0.68 ± 0.1 minutes and 0.63 ± 0.1 minutes, respectively).ConclusionThe 3 skin tools were quick and easy to use. The DAS skin correlated best with the skin VAS. The addition of CAT in a bivariate model containing the physician's global VAS was a statistically significant estimator of skin VAS score. We propose that there is scope for a new skin tool to be devised and tested, which takes into account the strengths of the 3 existing tools.

Highlights

Juvenile dermatomyositis (DM) is a rare inflammatory disease of childhood that predominantly affects muscles and skin but is a systemic multiorgan disease [1]. It is the Supported by Wellcome Trust UK, Action Medical Research UK, The Myositis Support Group UK, Arthritis Research UK, The Henry Smith Charity and Great Ormond Street Children’s Charity, a National Institute for Health Research Translational Research Collaborative grant, and the National Institute for Health Research Biomedical Research Centre at Great Ormond Street Hospital for Children NHS Foundation Trust and University College London
For patients whose skin disease was assessed at multiple time points, sensitivity of each tool to measure change over time was estimated by calculating the standardized response mean (SRM)
In the bivariate models of skin visual analog scale (VAS), the addition of the physician’s global VAS to the tools Cutaneous Assessment Tool (CAT) activity, Disease Activity Score (DAS) total, DAS skin, Myositis Intention to Treat Activity Index (MITAX) global, and MITAX skin strengthened each of those models, as revealed by the analysis of variance (ANOVA) comparisons of the bivariate models to their respective nested univariate models (Table 4)

Summary

Objective

To compare the abbreviated Cutaneous Assessment Tool (CAT), Disease Activity Score (DAS), and Myositis Intention to Treat Activity Index (MITAX) and correlate them with the physician’s 10-cm skin visual analog scale (VAS) in order to define which tool best assesses skin disease in patients with juvenile dermatomyositis. A total of 71 patients recruited to the UK Juvenile Dermatomyositis Cohort and Biomarker Study were included and assessed for skin disease using the CAT, DAS, MITAX, and skin VAS. The Childhood Myositis Assessment Scale (CMAS), manual muscle testing of 8 groups (MMT8), muscle enzymes, inflammatory markers, and physician’s global VAS were recorded. All 3 tools showed correlation with the physician’s global VAS and skin VAS, with DAS skin showing the strongest correlation with skin VAS. No correlations were found between the skin tools and inflammatory markers or muscle enzymes. We propose that there is scope for a new skin tool to be devised and tested, which takes into account the strengths of the 3 existing tools

INTRODUCTION

RESULTS

DISCUSSION