The primary systematic literature search strategy on the electronic databases
| Database | Search terms combination |
| Scopus | ({epidemiology} OR {prevalence} OR {incidence}) AND ({chronic fatigue syndrome} OR {myalgic encephalomyelitis} OR {CFS/ME} OR {ME/CFS}) |
| PubMed | ("Fatigue Syndrome, Chronic"[Mesh] AND (("Incidence" [Mesh] OR "Epidemiology"[Mesh] OR "epidemiology" [Subheading] OR "Prevalence "[Mesh] OR "Cross-Sectional Studies "[Mesh])) |
| Web of Science | ("epidemiology" OR "prevalence" OR "incidence") AND ("chronic fatigue syndrome" OR "myalgic encephalomyelitis" OR "CFS/ME" OR " ME/CFS") |
Mesh, medical subject headings.