Global disparities in the treatment of idiopathic inflammatory myopathies: results from an international online survey study
Authors: Ziade Nelly , Aoude Marc , Hmamouchi Ihsane , R. Naveen , Lilleker James B , Sen Parikshit , Joshi Mrudula , Agarwal Vishwesh , Kardes Sinan , Day Jessica , Makol Ashima , Milchert Marcin , Gheita Tamer , Salim Babur , Velikova Tsvetelina , Edgar Gracia-Ramos Abraham , Parodis Ioannis , Nikiphorou Elena , Chatterjee Tulika , Tan Ai Lyn , Saavedra Miguel A , Shinjo Samuel Katsuyuki , Knitza Johannes , Kuwana Masataka , Nune Arvind , Cavagna Lorenzo , Distler Oliver , Chinoy Hector , Agarwal Vikas , Aggarwal Rohit , Gupta Latika ,   the COVAD Study Group, Barman Bhupen , Singh Yogesh Preet , Ranjan Rajiv , Jain Avinash , Pandya Sapan C , Pilania Rakesh Kumar , Sharma Aman , Manesh Manoj M , Gupta Vikas , Kavadichanda Chengappa G , Patro Pradeepta Sekhar , Ajmani Sajal , Phatak Sanat , Goswami Rudra Prosad , Chowdhury Abhra Chandra , Mathew Ashish Jacob , Shenoy Padnamabha , Asranna Ajay , Bommakanti Keerthi Talari , Shukla Anuj , Pandey Arun Kumar R , Chandwar Kunal , Cansu Döndü Üsküdar , Pauling John D , Wincup Chris , Del Papa Nicoletta , Sambataro Gianluca , Fabiola Atzeni , Govoni Marcello , Parisi Simone , Bocci Elena Bartoloni , Sebastiani Gian Domenico , Fusaro Enrico , Sebastiani Marco , Quartuccio Luca , Franceschini Franco , Sainaghi Pier Paolo , Orsolini Giovanni , De Angelis Rossella , Danielli Maria Giovanna , Venerito Vincenzo , Traboco Lisa S , Wibowo Suryo Anggoro Kusumo , Tehozol Erick Adrian Zamora , Serrano Jorge Rojas , García-De La Torre Ignacio , Loarce-Martos Jesús , Prieto-González Sergio , Gonzalez Raquel Aranega , Yoshida Akira , Nakashima Ran , Sato Shinji , Kimura Naoki , Kaneko Yuko , Tomaras Stylianos , Gromova Margarita Aleksandrovna , Aharonov Or , Hoff Leonardo Santos , Giannini Margherita , Maurier François , Campagne Julien , Meyer Alain , Nagy-Vincze Melinda , Langguth Daman , Limaye Vidya , Needham Merrilee , Srivastav Nilesh , Hudson Marie , Landon-Cardinal Océane , Shaharir Syahrul Sazliyana , Zuleta Wilmer Gerardo Rojas , Silva José António Pereira , Fonseca João Eurico , Zimba Olena 
Published: May 2023

Abstract

Objectives
We aimed to explore current practice and interregional differences in the treatment of idiopathic inflammatory myopathies (IIMs). We triangulated these observations considering countries' gross national income (GNI), disease subtypes, and symptoms using patient-reported information.

Methods
A cross-sectional ancillary analysis of the ‘COVID-19 vaccination in auto-immune disease’ (COVAD) e-survey containing demographic characteristics, IIM subtypes (DM, PM, IBM, anti-synthetase syndrome [ASSD], immune-mediated necrotizing myopathy [IMNM], overlap myopathies [OM]), current symptoms (surrogate for organ involvement) and treatments (corticosteroids [CS], immunomodulators [IM], i.e. antimalarials, immunosuppressants [IS], IVIG, biologic treatments and targeted-synthetic small molecules). Treatments were presented descriptively according to continents, GNI, IIM and organ involvement, and associated factors were analysed using multivariable binary logistic regressions.

Results
Of 18 851 respondents from 94 countries, 1418 with IIM were analysed (age 61 years, 62.5% females). DM (32.4%), IBM (24.5%) and OM (15.8%) were the most common subtypes. Treatment categories included IS (49.4%), CS (38.5%), IM (13.8%) and IVIG (9.4%). Notably, treatments varied across regions, GNI categories (IS mostly used in higher-middle income, IM in lower-middle income, IVIG and biologics largely limited to high-income countries), IIM subtypes (IS and CS associated with ASSD, IM with OM and DM, IVIG with IMNM, and biologic treatments with OM and ASSD) and disease manifestations (IS and CS with dyspnoea). Most inter-regional treatment disparities persisted after multivariable analysis.

Conclusion
We identified marked regional treatment disparities in a global cohort of IIM. These observations highlight the need for international consensus-driven management guidelines considering patient-centred care and available resources.