Appraisal of Long COVID: Lessons to be Learned from Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

OBJECTIVE(S): Little is known regarding after-effects of Long-COVID-19 (LC), while ME/CFS has been extensively researched. We performed a rigorous scoping review to inform a better definition of symptomatology of LC and cross-cutting similarities with ME/CFS. Our objective was to review the National Institutes of Health (NIH) ME/CFS Common Data Elements (CDEs), identify Patient Reported Outcome Measures (PROMs) and link items to the World Health Organization (WHO) International Classification of Functioning, Disability and Health (ICF) codes to inform efforts to define LC. DATA SOURCES: NIH ME/CFS CDEs (Jan. 2020), Google Scholar, PubMed - search terms: Long COVID and ME/CFS. STUDY SELECTION: A review of 119 NIH ME/CFS CDEs applied the following inclusion criteria: 1) PROM based; 2) assess symptomatology; 3) specific to adults 18 years and over; 4) no visual or pictographic scales. DATA EXTRACTION: Of the 119 NIH ME/CFS CDEs, 38 met review criteria; items were entered into an Excel spreadsheet. Five researchers independently coded items using ICF linking rules and resolved discrepancies using a consensus-based process. DATA SYNTHESIS: Six articles specifically compared LC and ME/CFS for symptom overlap. Similarities between ME/CFS and Long COVID symptoms include: fatigue, post exertional malaise (PEM), cognitive symptoms, sleep dysfunction, pain, noise and light hypersensitivity, orthostatic intolerance, cardiac, gastrointestinal and immune pathologies. The 944 items from 38 PROM CDEs were coded based on common ME/CFS and LC symptoms. The percent of items linked to one or more ICF categories (1288 codes) was as follows: Body Function (b codes) 73%: Fatigability, N=252 (20%); Cognitive functions, N=234 (18%); Sleep functions, N=139, 11%; and Pain, N=119, (9%). Activity and Participation (d codes), N=332, (26%). Environment (e codes), N=11, 0.9%. CONCLUSIONS: The ICF provides a common language to assess ME/CFS and LC cross-cutting symptoms and their impact on body function, activity and participation. This review of ME/CFS CDE's can help identify common symptoms, such as PEM, and encourage appropriate symptom management to prevent cycles of overexertion and relapse for those with LC. AUTHOR(S) DISCLOSURES: The authors have no conflicts of interest to declare.