Table 5.

Illness characteristics among CFS subjects at initial classification and among fatigued subjects at follow-up

Characteristic	Initial classification (N = 65)	1-year follow-up (N = 49)	2-years follow-up (N = 29)	3-years follow-up (N = 18)
Fatigue duration in years (%)
#2	18.5	2.0	0.0	0.0
2.1–5	23.1	20.4	27.6	11.1
5.1–10	30.8	34.7	31.0	44.4
>10	27.7	42.9	41.4	44.4
Median (interquartile range)	6 (3.6–10.8)	7.5 (5.3–13.2)	8.0 (4.8–12.9)	9.4 (7.2–13.9)
Rest did not relieve fatigue a lot (%)	100	95.2	96.6	94.4
Since fatiguing illness began, it interfered a lot with (%)
Social activities	76.9	51.0*	62.1	44.4
Personal activities	76.9	69.4	58.6	55.6
Work activities	66.2	42.9*	55.2	33.3
Educational activities	40	28.6*	27.6	27.8
Median number of activities affected by fatigue	3	2†	3	1.5
Currently employed (%)	63.1	61.2	55.2	55.6
Unemployed because of fatiguing illness (%)	16.9	18.4	13.8	16.7
Fatigue Assessment Instrument subscales, mean (standard deviation)
Severity	5.9 (0.9)	5.6 (0.8) †	5.8 (0.8)	5.4 (1.0)
Situation Specific	4.3 (1.3) ‡	4.3 (1.5)	4.5 (1.4)	3.8 (1.4)
Psychological consequences	6.0 (1.0)	6.0 (1.1)	6.2 (0.7)	5.8 (0.9)
Responds to rest/sleep	3.8 (1.8) ‡	3.3 (1.7)	3.8 (2.0)	3.4 (1.9)

* p < 0.05 in McNemar's test † p < 0.01 in paired t-test ‡ p < 0.05 in t-test, compared with published data