Table 6. The sensitivity, specificity and predictive value determinated by cut-off levels for IL-8 concentration before surgery and the changes of IL-8 concentration (ΔIL-8).

Results	IL-8	ΔIL-8
True negative	18 (24%)	19 (26.8%)
True positive	30 (41%)	31 (44%)
False negative	18 (25%)	17 (24%)
False positive	6 (8%)	4 (5.6%)
All results	73	71
Sensitivity	63%	65%
Specificity	75%	83%
Positive predictive value (PPV)	83%	89%
Negative predictive value (NPV)	50%	53%
Accuracy (Acc)	49%	49%