Measures of Overall Illness Severity and Burden for ME/CFS: A Scoping Review

Consensus has not been established on measures of illness severity and burden for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), which is characterized by a wide range of symptoms including post-exertional malaise, unrefreshing sleep, and cognitive impairment. A scoping review was conducted to systematically evaluate the measurement of illness severity and burden in individuals with ME/CFS.

A literature search was conducted following PRISMA-ScR guidelines across five academic databases and one patient-organization-led website (with no restrictions on publication date; restricted to English language studies, and excluding review articles). Records were imported into Covidence, a systematic and scoping review data management tool, with studies retained if they evaluated an ME/CFS population and explicitly measured illness severity or illness burden. Information from each source was extracted and relevant measures were evaluated.

From the reviewed literature, 190 full-text articles met the final inclusion criteria and were retained for analysis. The most frequently utilized tools for evaluating illness severity and burden in individuals with ME/CFS were the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) and the Sickness Impact Profile (SIP). Additional prominent instruments identified across the literature include disease-specific measures such as the DePaul Symptom Questionnaire (DSQ) and generic health-related quality of life indices like the EuroQoL 5-Dimension (EQ-5D-5L).

Significant discrepancies persist in how illness severity and illness burden are operationalized in ME/CFS research. The reliance on generic instruments often obscures core symptom domains like post-exertional malaise (PEM), while inconsistent standards limit cross-comparability. Establishing standardized, disease-specifici illness metrics is critical to accurately capturing the true burden of illness and advancing rigorous clinical research.