Effect of Changing the Cutoff Point of the WBC Count in Patients Suspected of Having Appendicitis
WBC Cutoff* | Sensitivity | Specificity | LR+ | LR- |
|---|---|---|---|---|
> 10,500 | 84% | 53.13% | 1.79 | 0.3 |
> 11,500 | 78% | 62.5% | 2.13 | 0.32 |
> 12,850 | 68% | 75% | 2.72 | 0.43 |
> 13,400 | 61.33% | 78.12% | 2.86 | 0.45 |
> 14,300 | 56.67% | 81.25% | 3.2 | 0.49 |
* Various cutoff points are selected for a continuous variable such as WBC count; results above the cutoff point are considered positive and those below the cutoff point are considered negative. Values listed are per microliter of blood. | ||||
LR = likelihood ratio; WBC = white blood cell. | ||||
Adapted from Keskek M, Tez M, Yoldas O, et al: Receiver operating characteristic analysis of leukocyte counts in operations for suspected appendicitis. American Journal of Emergency Medicine 26:769–772, 2008. | ||||