A brief, comprehensive measure of post-exertional malaise

Aim: Post-exertional malaise (PEM) has been a challenging construct to measure, particularly with self-report instruments, which have the benefits of being less expensive and less invasive than cardiopulmonary exercise tests. Existing PEM questionnaires have often been used for diagnostic purposes and less frequently as outcome measures. Few self-report PEM measures address comprehensive PEM domains, including types of triggers, duration of symptoms, delayed symptom onset, number of symptoms, frequency and severity of symptoms, as well as whether pacing or other strategies reduce or eliminate PEM. Without characterizing these features, salient aspects of PEM would be overlooked. However, efforts to assess all these domains can be time-consuming and potentially burdensome. Methods: The current study offers investigators a brief but comprehensive instrument of critical PEM domains, called the DePaul Symptom Questionnaire (DSQ)-PEM-2, to assess PEM. Validation data were derived from a large sample of individuals with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Results: The DSQ-PEM-2 was developed using an existing dataset of individuals with ME, CFS, or both ME and CFS, allowing comprehensive coverage of key PEM domains. Conclusions: The DSQ-PEM-2 can be used either for diagnostic purposes or as an outcome measure. The instrument’s time frames for symptom manifestation can be adapted to suit a variety of research or clinical contexts. Future validation studies need to include a healthy control group.