Murdock, Kyle W, Wang, Xin Shelley, Shi, Qiuling et al. · Quality of life research : an international journal of quality of life aspects of treatment, care and rehabilitation · 2017 · DOI
Researchers tested three common questionnaires that measure fatigue and symptoms in ME/CFS patients to see which ones work best. They found that two popular questionnaires had problems—many patients scored so high they hit the ceiling (meaning the test couldn't measure if they got worse), and the questions weren't reliable. The DePaul Symptom Questionnaire worked much better, especially at measuring post-exertional malaise (the worsening of symptoms after activity), and could reliably distinguish ME/CFS patients from healthy people.
Reliable symptom measurement is fundamental to ME/CFS research and clinical care, yet existing tools often fail to capture the full range of disease severity. This study identifies which questionnaires actually work for ME/CFS patients and which ones miss important information, helping clinicians and researchers choose better assessment tools. The findings particularly highlight post-exertional malaise as a key distinguishing feature that should be measured carefully in future ME/CFS studies.
This cross-sectional study does not establish whether these questionnaires can track changes in symptoms over time (responsiveness), nor does it prove causation or mechanisms underlying measurement problems. The results apply specifically to the patient population studied and may not generalize to all ME/CFS patients or other fatigue-related conditions. Additionally, the study does not determine whether improving these measures will improve clinical outcomes.