The "Report Guide for Clinicians" by the IOM and a part of the Institute of Medicine report states: "Despite the absence of a specific objective alteration in sleep architecture, the data are strong that the complaint of unrefreshing sleep is universal among patients with ME/CFS (SEID) when questions about sleep specifically address this issue. While polysomnography is not required to diagnose ME/CFS (SEID), its use to screen for treatable sleep disorders when indicated is appropriate. Diagnosis of a primary sleep disorder does not rule out a diagnosis of ME/CFS (SEID)."
- 2016, Prevalencia de síntomas de fatiga crónica / encefalomielitis miálgica (SFC/EM) y su relación con factores ocupacionales en trabajadores en una empresa de vigilancia en Bogotá, Colombia (Jonathan Kerr) Note: This study did not use PEM as a inclusionary symptom nor did it use any Definitions of ME and CFS including the most symptom liberal of valid definitions, SEID. The only entry criteria noted were fatigue and muscle pain which seem to be the broadest and loose of symptom definitions Reeves criteria and Oxford criteria.
- 1997, Sleep anomalies in the chronic fatigue syndrome. A comorbidity study.
- 2016, How I sleep at night