Table 5 Illness characteristics among CFS subjects at initial classification and among fatigued subjects at follow-up

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)