Introduction
Methods
Sample
Measures
Data analysis
Results
Descriptive statistics
Item | Mean (SD) | Factor | |||
---|---|---|---|---|---|
Physical fatigue | Low energy | Mental fatigue | |||
1. | Problems with tiredness | 2.27 (.68) |
.70**
| .11 | −.01 |
2. | Rest more | 2.22 (.69) |
.87**
| −.01 | −.01 |
3. | Feel sleepy or drowsy | 1.85 (.83) |
.44**
| .27** | .09 |
4. | Problems starting things | 1.54 (.98) | .01 |
.72**
| .00 |
5. | Lack energy | 1.72 (.97) | −.19 |
.97**
| −.01 |
6. | Less strength in muscles | 1.67 (.97) | .09 |
.45**
| .12** |
7. | Feel weak | 1.65 (.98) | .02 |
.66**
| .09 |
8. | Hard to concentrate | 1.53 (.93) | −.01 |
.43**
|
.46**
|
9. | Make slips of the tongue | 1.04 (.96) | −.01 | .02 |
.86**
|
10. | Hard to find the correct word | .94 (.95) | −.01 | −.03 |
.88**
|
11. | Poor memory | 1.57 (.99) | .06 | .21** |
.57**
|
Factor structure
Model |
χ
2
| df | CFI | TLI | RMSEA (90 % CI) | SRMR | BIC |
---|---|---|---|---|---|---|---|
CFA | |||||||
two-factor | 823.2** | 43 | .863 | .824 | 120 (.113–.127) | .068 | 30,331.9 |
three-factor | 569.8** | 41 | .907 | .875 | 101 (.094–.109) | .061 | 30,034.3 |
Revised three-factor | 482.5** | 40 | .922 | .893 | 094 (.086–.101) | .059 | 29,938.3 |
ESEM | |||||||
two-factor | 491.3** | 34 | .919 | .870 | 103 (.095–.112) | .039 | 30,018.5 |
three-factor | 263.6** | 25 | .958 | .908 | 087 (.078–.097) | .024 | 29,761.1 |
Revised three-factor | 138.7** | 24 | .980 | .954 | 062 (.052–.072) | .018 | 29,656.1 |
ESEM + covariates | 228.5** | 64 | .974 | .956 | 045 (.039–.052) | .018 | 29,632.1 |
Convergent validity
Outcome | Physical fatigue | Low energy | Mental fatigue |
---|---|---|---|
Anxiety | .32** | .47** | .46** |
Depression | .31** | .50** | .42** |
Exhaustion | .41** | .59** | .42** |
Sleep disturbance | .21** | .30** | .25** |
Physical quality of life | −.21** | −.23** | −.20** |
Mental quality of life | −.33** | −.53** | −.42** |