New parameter in diagnosis of acute appendicitis: Platelet distribution width

Table 1 Comparison of the laboratory values between the groups

Variable	Group I	Group II	Group III	P values
	(n = 295)	(n = 100)	(n = 100)	I vs II	I vs III	II vs III	Overall
White blood cell count, × 109/μL	12.9 (3.1-25.7)	11.5 (5.2-20.0)	7.5 (3.5-13.6)	0.032	< 0.001	< 0.001	< 0.001
Neutrophil, %	73.9 (18.0-93.0)	67.9 (45.0-87.9)	57.6 (21.0-76.0)	0.031	< 0.001	< 0.001	< 0.001
Mean platelet volume, fL	8.5 (6.1-14.2)	8.9 (6.0-13.0)	8.9 (6.9-14.5)	NS	0.001	NS	0.003
Platelet distribution width, %	49.0 (10.6-86.5)	40.8 (12.8-87.9)	18.4 (10.3-62.5)	< 0.001	< 0.001	< 0.001	< 0.001

Data are presented as mean (range). NS: Not significant.

Table 2 Diagnostic comparison of blood parameters

Parameter	Cutoff	AUC	Sensitivity	Specificity	PPV	NPV	PLR	NLR	DA
		(95%CI)	(%)	(%)	(%)	(%)			(%)
White blood cell count	10.6 × 109/μL	0.87 (0.84-0.91)	73.1	94	97.1	56.0	12.1	0.3	78
Neutrophil	69.85%	0.87 (0.84-0.91)	70.0	96	97.9	54.2	23.0	0.3	76
Mean platelet volume	8.98 fL	0.62 (0.55-0.68)	29.5	49	61.1	20.1	0.5	4.5	34
Platelet distribution width	32.15%	0.95 (0.92-0.98)	97.1	93	97.4	92.1	13.8	0.0	96

AUC: Area under the receiver operating characteristic curve; DA: Diagnostic accuracy; NLR: Negative likelihood ratio; NPV: Negative predictive value; PLR: Positive likelihood ratio; PPV: Positive predictive value.