| ObjectiveJuvenile Dermatomyositis(JDM)is a non-purulent chronic autoimmune disease,which is the most common of the juvenile idiopathic inflammatory myopathies.The disease is mainly characterized by typical skin rash and progressive muscle weakness,and it can also affect lungs,gastrointestinal tract,heart and other organs.At present,different assessment tools are used to evaluate the activity and severity of JDM.This study is aimed to test their validity and reliability,then estimate clinical application values of these tools.MethodsCollect and filtrate children diagnosed with JDM/JPM visiting Ren Ji Hospital Affiliated to Shanghai Jiao Tong University School of Medicine between Jan,2008 and Sep,2018;then applying MDAAT/DAS/CMAS to assess disease activity of JDM patients on the first day and after 24~48h when they are in hospital;finally,data collection and analysis to test validity and reliability of three tools,and analyze the relationship with each other,meanwhile explore influence factors of CMAS.Results(1)Characteristics of study subjects: of these 35 JDM children,2 with JPM,4 with CADM,29 with JDM,15 children are male,and 20 are female,the female to male ratio is 1.33:1,and the average age at disease onset was 3.16±1.45 years,the elevation of serum levels of muscle enzymes at the disease onset was 50%~95.5%,the proportion of first symptoms onset with rash,muscle weakness,and both were60%,37%,3% respectively.(2)Internal consistency: Cronbach?values were 0.862,0.851,0.947(>0.7)for MDAAT,DAS,CMAS respectively,and it showed correlation well among items.(3)Test-retest reliability: Intraclass correlation coefficient(ICC)for MDAAT,DAS,CMAS was 0.940,0.957,0.942(>0.7)respectively,so it showed high stability of these tools.(4)Construct validity: It was assessed by exploratory factor analysis.Components was extracted by principal component analysis.Communality was 0.616 ~0.909,0.644~0.933,0.672~0.953(>0.4)respectively;the cumulative variance from the extracted components was 85.851%,82.271%,84.206%(>50%)respectively,and value of factor loading on each factor was0.427 ~ 0.946,0.464 ~ 0.947,0.672 ~0.953(>0.4)respectively.It showed the MDAAT,DAS,CMAS according with the original questionnaires.(5)Responsiveness: Scores between pre-therapy and post-therapy were assessed by paired t-test.P values were less than 0.05 and it showed responsiveness well.(6)Analysis of correlation: the relationship between three measures tools is moderate to strong,and these assessment tools are lowly or moderately correlated with muscle enzymes.(7)Analysis of influence factors: Logistic regression analysis was performed on age,pulmonary interstitial lesions,arthritis,calcinosis and dysphagia.The OR value of pulmonary interstitial lesions was 13.516,indicating that pulmonary interstitial lesions were the main factors affecting the evaluation results and leading to poor prognosis.Conclusions(1)The assessment tools,including MDAAT,DAS,CMAS,have a good reliability,validity and responsiveness,and correlated well with each other.(2)They could be used to respectively quantify the activity and severity of JDM/PM,furthermore,to evaluate and adjust treatment regimes.(3)Pulmonary interstitial lesions are the main factors affecting the evaluation results,so it's necessary to evaluate pulmonary systems as soon as possible at disease onset,and provide treatment in time. |
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