Sample characteristics
One subject attending the clinic was dropped from analysis because missing data did not permit scoring of any factor in the SAQ. Demographic and clinical characteristics of the remaining 339 subjects in the sample are shown in Table 1 along with the distribution of these characteristics by fatigue group. Over half the fatigued subjects (145/277, 52.3%) as well as one not fatigued subject had exclusionary medical or psychiatric conditions identified during the clinical evaluation. Medical exclusions identified during the clinic visit included abnormal blood or urine tests, abnormal Romberg test, adrenal insufficiency, bladder tumor, BMI = 47, cerebral palsy, chronic hepatitis, emphysema, heart disease within 2 years of evaluation, hypertension, hypothyroidism, inflammatory bowel disease, kidney cancer, lupus, melanoma, uncontrolled diabetes, rheumatoid arthritis, self-reported sleep apnea and narcolepsy, and major surgery within the past year. Psychiatric disorders included anorexia or bulimia nervosa, bipolar disorder, delusional disorder, and major depressive disorder with melancholic features.