The utility of patient-reported outcome measures among patients with myalgic encephalomyelitis/chronic fatigue syndrome.
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
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.