Scoping review of the emerging definition of long COVID: implications for future research and clinical practice

Introduction: Long COVID, Post-COVID19 syndrome and prolonged COVID-19, are concepts classified as the set of signs and symptoms that persist after an acute episode of COVID-19 disease. Objective: To describe what definitions have been published for the term "long COVID". Methods: The PRISMA ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) was used as a base for a scoping review, as suggested by Joanna Briggs Institute. A search of databases, Medline via PubMed, Embase, SciELO and The Cochrane Library was undertaken. The data registry and synthesis of the results was carried out independently by two reviewers. Results: Following removal of duplicates, 896 articles were retrieved of which 91 met the eligibility principles and 51 of which included a definition. At least four characteristics of the definitions were identified: time or term, organs affected, symptoms and clinical manifestations. Conclusions: The review identified many concepts and definitions of "long COVID". These findings show that there is lack of consensus on the definition of long COVID-19.