A population-based study of the clinical course of chronic fatigue syndrome

Table 6 Changes in CFS classification (%)

Classification	1-year follow-up (N = 59)	2-years follow-up (N = 39)	3-years follow-up (N = 24)
CFS	32.2	20.5	20.8
Insufficient symptoms or fatigue severity	30.5	30.8	37.5
Not fatigued	15.3	18.0	20.8
Exclusionary conditions
Permanent medical or psychiatric*	8.5	15.4	16.7
Temporary medical†	13.6	15.4	4.2

*Permanent exclusions include bulimia, bipolar disease, chronic hepatitis, body mass index = 47, Sjögren's syndrome, diabetes with complications, multiple sclerosis, inflammatory bowel disease (2 subjects), sleep apnea or narcolepsy (3 subjects) and major depressive disorder with melancholia (3 subjects) † Temporary exclusions include abnormal urinalysis, beta-blocker medication, results for positive Romberg's test, rheumatoid factor, abnormal liver function, hypertension, breast mass, multiple myeloma, and thyroid disease.