Toward a definition of a core outcome set in neuromyelitis optica spectrum disorder: a scoping review protocol

OBJECTIVE: This scoping review will examine the available evidence to identify the main outcomes, their definitions, and how they were measured, along with the values, preferences, and experiences, of adult patients with aquaporin-4 immunoglobulin G antibody (AQP4-IgG)-seropositive neuromyelitis optica spectrum disorder (NMOSD). INTRODUCTION: NMOSD encompasses a group of inflammatory central nervous system disorders that cause optic neuritis and myelitis. Therapies have different mechanisms of action, but their efficacy has not been fully compared due to variability of outcomes used in randomized controlled trials. No attention has been paid to the selection of outcomes, and primary and secondary outcomes commonly depend on the researcher's preferences. This issue could be addressed through core outcome sets (COS) which establish the key outcomes that should be assessed in randomized controlled trials. Such COS are currently lacking, and this review will provide a better understanding of COS for NMOSD to facilitate their further development and standardization. ELIGIBILITY CRITERIA: The review will consider qualitative and quantitative primary studies, conducted in any clinical context, reporting on adult patients with AQP4-IgG-seropositive NMOSD; exploring outcomes, their definitions, and how they were measured; and examining the values, preferences, and experiences of patients. METHODS: The review will follow the JBI methodology for scoping reviews. Databases to be searched will include Cochrane CENTRAL (Ovid), MEDLINE (Ovid), Embase (Ovid), and PsycINFO (EBSCOhost); gray literature (medRxiv) will also be searched. Three reviewers will independently screen titles and abstracts, and then full texts. Data will be extracted using a customized tool. Outcomes will be classified using a taxonomy system. A narrative summary will accompany the tabulated and charted results. REVIEW REGISTRATION: COMET https://www.comet-initiative.org/Studies/Details/3440). PROTOCOL REGISTRATION: OSF https://osf.io/knrhc/.