Measuring Post-Exertional Malaise with DePaul Symptom Questionnaires: Challenges and Opportunities

Following mental or physical exertion, patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) experience Post-Exertional Malaise (PEM). Although self-report questions represent less expensive and invasive procedures to assess PEM, variability in the wording of the symptom can cause reliability and validity problems. If different PEM measures are used in studies, this could create difficulties in replicating findings, identifying biomarkers, and determining effective treatments for patients. The objective of this article is to describe the challenges and opportunities of the PEM questions of the DePaul Symptom Questionnaires (DSQ) in specific. The five PEM DSQ items can identify 97% of patients with ME/CFS. A brief DSQ-PEM instrument has now been constructed that consists of five DSQ PEM items and five DSQ supplementary items such as symptom duration and how quickly patients would recover from activities. A more comprehensive instrument called the DePaul Post-Exertional Malaise Questionnaire assesses a more comprehensive list of PEM triggers and the duration and length of recovery time from PEM. In this article, we show how the DSQ’s PEM self-report items can provide clues to ME/CFS pathophysiology as well as how these items can be used as outcome measures. Future research should focus on contrasting and comparing different ways of eliciting PEM, assessing relationships between PEM self-report questionnaires and biomarkers, and examining the impact of treatment trials on PEM.