Table 1

Clinical and epidemiological characteristics of 23 CFS women.

Characteristic
Number

Type of fatigue onset a

Gradual
12
Sudden
10
Age, years b

≤50
12
>50
11
Duration of illness b

≤10
15
>10
8
No. of CFS symptoms b

4
8
5
7
≥6
8
Body mass index c

Normal
6
Overweight
7
Obese
10
Illness group d

1
4
2
19

a Onset type defined as sudden (self-reported as developing fatigue in = 1 week) or gradual (developing fatigue over a period = 1 month). One subject described onset as between 1 week and one month and was not classified for this stratification. b Further stratification and analysis using the Kruskal-Wallis nonparametric test did not show different results. c Analysis performed on BMI <25 (normal) compared with >30(obese). Subjects considered overweight were not included in this particular analysis. Further stratification and analysis using the Kruskal-Wallis test showed no significant differences between the groups (results not shown.). d Illness group defined by factor analysis of symptoms followed by cluster analysis [4].

Whistler et al. Journal of Translational Medicine 2003 1:10   doi:10.1186/1479-5876-1-10