Diagnostic delay of Myositis: protocol for an integrated systematic review

AbstractIdiopathic inflammatory myopathies (IIM) described as “inflammatory myositis”, are a heterogeneous group of rare muscular autoimmune diseases characterized by skeletal muscle inflammation. Its complex characteristics with lack of accurate diagnostic tests, unified classification system, and comprehensive widely used diagnostic criteria could lead to diagnostic delay. This study will review diagnostic delay in Myositis and provide an overview and clearer insight of patients’ experiences, causes and consequences of diagnostic delay in Myositis.Methods and analysisThe literature source will be a systematic search of PubMed/Medline, Scopus, ProQuest, and sources of grey literature, conducted from database inception to 15th of December 2021 without restrictions on publication date. All study types (qualitative and quantitative) except review articles, examining diagnostic delay, incorrect diagnosis, missed diagnosis or slow diagnosis of all types of myositis in all ages will be included. Evidence of patients’ experiences associated with diagnostic delay will also be examined. Studies in languages other than English, German and Indonesian will be excluded. Outcomes will be diagnostic delay time, patients’ experiences, and causes and consequences associated with diagnostic delay in Myositis. Two review authors will independently screen the titles and abstracts of search results against the inclusion criteria. The Mixed Methods Appraisal Tool (MMAT) will be used to appraise selected studies. Two independent authors will extract data using a pre-piloted data extraction tool. If sufficient quantitative data is available, a meta-analysis will be conducted along with subgroup analysis including pooled diagnostic delay in each type of Myositis. Qualitative data will be analysed in line with meta-aggregation methods. If data is insufficient, a narrative synthesis will be conducted.Ethics and disseminationAs a systematic review, ethical approval was not required. Findings of the study will be disseminated through publications in peer-reviewed journals, conferences, and symposia.PROSPERO Registration numberCRD42022289830Strengths and limitations of this studyThe protocol was developed in accordance with Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols guidelines and the Cochrane Handbook for Systematic Reviews.Examination of both quantitative and qualitative literature will enable insight into the causes and consequences, and patients’ experiences associated with diagnostic delay of Myositis.In some case studies, it will be necessary to manually calculate diagnostic delay according to the date of symptom onset and the date of diagnosis.The primary limitation of this study is that it will not capture evidence that is not published, or from situations when an accurate diagnosis of Myositis is not made.The review will be limited to English, German, and Indonesian studies.