OptimisAtion of Diagnostic Accuracy in idioPathic inflammaTory myopathies (ADAPT study): a protocol for a prospective diagnostic accuracy study of multimodality testing in patients suspected of a treatable idiopathic inflammatory myopathy
Frank F Smithuis,
Anneke J van der Kooi,
Joost Raaphorst,
Ivo N van Schaik,
Marianne de Visser,
Paul A Baars,
Patrick M M Bossuyt,
Eleonora Aronica,
Johannes H T M Koelman,
Camiel Verhamme,
Hannah A W Walter,
Renske G Kamperman,
Wouter V Potters,
Ester M M van Leeuwen
Affiliations
Frank F Smithuis
3 Amsterdam Collaboration for Health and Safety in Sports (ACHSS), AMC/VUmc IOC Research Center, Amsterdam, The Netherlands
Anneke J van der Kooi
Department of Neurology and Clinical Neurophysiology, Amsterdam UMC Locatie AMC, University of Amsterdam, Amsterdam, The Netherlands
Joost Raaphorst
4 Department of Neurology, Amsterdam Neuroscience, Amsterdam UMC, Amsterdam, Noord-Holland, The Netherlands
Ivo N van Schaik
Department of Neurology and Clinical Neurophysiology, Amsterdam UMC Locatie AMC, University of Amsterdam, Amsterdam, The Netherlands
Marianne de Visser
Department of Neurology and Clinical Neurophysiology, Amsterdam University Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
Paul A Baars
Department of Experimental Immunology, Amsterdam Institute for Infection & Immunity, Amsterdam UMC, Amsterdam UMC Locatie AMC, Amsterdam, North Holland, The Netherlands
Patrick M M Bossuyt
professor of clinical epidemiology
Eleonora Aronica
Department of (Neuro)Pathology, Amsterdam University Medical Centre, Amsterdam Neuroscience, Amsterdam UMC Locatie AMC, Amsterdam, North Holland, The Netherlands
Johannes H T M Koelman
Department of Neurology and Clinical Neurophysiology, Amsterdam University Medical Centre, University of Amsterdam, Amsterdam Neuroscience, Amsterdam UMC Locatie AMC, Amsterdam, The Netherlands
Camiel Verhamme
Department of Neurology and Clinical Neurophysiology, Amsterdam UMC Locatie AMC, University of Amsterdam, Amsterdam, The Netherlands
Hannah A W Walter
Department of Neurology and Clinical Neurophysiology, Amsterdam UMC Locatie AMC, University of Amsterdam, Amsterdam, The Netherlands
Renske G Kamperman
Department of Neurology and Clinical Neurophysiology, Amsterdam UMC Locatie AMC, University of Amsterdam, Amsterdam, The Netherlands
Wouter V Potters
Department of Neurology and Clinical Neurophysiology, Amsterdam University Medical Centre, University of Amsterdam, Amsterdam Neuroscience, Amsterdam UMC Locatie AMC, Amsterdam, The Netherlands
Ester M M van Leeuwen
Department of Experimental Immunology, Amsterdam Institute for Infection & Immunity, Amsterdam UMC, Amsterdam UMC Locatie AMC, Amsterdam, North Holland, The Netherlands
Introduction Idiopathic inflammatory myopathies (IIMs) excluding inclusion body myositis (IBM) are a group of heterogeneous autoimmune disorders characterised by subacute-onset and progressive proximal muscle weakness, which are frequently part of a multisystem autoimmune disorder. Reaching the diagnosis can be challenging, and no gold standard for the diagnosis of IIM exists. Diagnostic modalities include serum creatine kinase activity, muscle imaging (MRI or ultrasound (US)), electromyography (EMG), myositis autoantibody testing and muscle biopsy. Several diagnostic criteria have been developed for IIMs, varying in reported sensitivity and specificity.Hypothesis We hypothesise that an evidence-based diagnostic strategy, using fewer and preferably the least invasive diagnostic modalities, can achieve the accuracy of a complete panel of diagnostic tests, including MRI, US, EMG, myositis-specific autoantibody testing and muscle biopsy.Methods and analysis The OptimizAtion of Diagnostic Accuracy in idioPathic inflammaTory myopathies study is a prospective diagnostic accuracy study with an over-complete study design. 100 patients suspected of an IIM excluding IBM will be included. A reference diagnosis will be assigned by an expert panel using all clinical information and all results of all ancillary tests available, including 6 months of follow-up. Several predefined diagnostic strategies will be compared against the reference diagnosis to find the optimal diagnostic strategy.Ethics and dissemination Ethical approval was obtained from the medical ethics committee of the Academic Medical Centre, University of Amsterdam, The Netherlands (2019-814). The results will be distributed through conference presentations and peer-reviewed publications.Trial registration number Netherlands trial register; NL8764.
