Table 2

Predicted and observed fatigue 6 months after acute Epstein-Barr virus-infection

Observed
Fatigued (CFQ≥4)Not fatigued (CFQ<4)CFQ-score (95 % CI)
Prediction
 Likely fatigued* (%)14 (66.7)7 (33.3)5.6 (3.9 to 7.3)
 Unsurely fatigued* (%)22 (61.1)14 (38.9)4.8 (3.7 to 5.8)
 Not fatigued* (%)40 (38.5)64 (61.5)3.2 (2.7 to 3.8)
Sensitivity†=18.4%Specificity†=75.3%
  • *Referring medical practitioner’s guess; no=not fatigued, don’t know=unsurely fatigued, yes=likely fatigued.

  • †Sensitivity and specificity are calculated after an intention-to-diagnose principle5; when calculating sensitivity, unsurely fatigued is included in the false negatives, while in calculation of specificity those predicted unsurely fatigued is included in false positives.

  • CQF, Chalder Fatigue Questionnaire.