Sensitivity of the suspected blood indicator: An experimental study

Table 1 Detection rates of red spots by suspected blood indicator according to the background color

Color	Detection rate (%)	Rank
Very pale yellow	16/150 (10.7)	6
Yellow	28/150 (18.7)	3
Very pale magenta	64/150 (42.7)	1
Light grayish pink	19/150 (12.7)	4
Burnt sienna	36/150 (24.0)	2
Deep brown	18/150 (12.0)	5
Dark brown	5/150 (3.3)	7
Total	186/1050 (17.7)	P < 0.001

Table 2 Differences in detection rate among background colors using Bonferroni’s correction

Color	Detection rate (%)	Dark brown	Very pale yellow	Deep brown	Light grayish pink	Yellow	Burnt sienna	Very pale magenta
Dark brown	3.3	1	0.0130	0.0049	0.0029	0.0000	0.0000	0.0000
Very pale yellow	10.7		1	0.7161	0.5901	0.0506	0.0023	0.0000
Deep brown	12.0			1	0.8609	0.1097	0.0069	0.0000
Light grayish pink	12.7				1	0.1535	0.0113	0.0000
Yellow	18.7					1	0.2603	0.0000
Burnt sienna	24.0						1	0.0006
Very pale magenta	42.7							1
Adjusted α	0.002381

Table 3 Diagnostic accuracy of suspected blood indicator according to the literature (%)

	Liangpunsakul et al[8]		Signorelli et al[12]		D’Halluin et al[10]		Buscaglia et al[9]		Kim et al[11]
	OL	AB	OL	AB	OL	AB	OL	AB	OL	AB
Sensitivity	25.7	81.2	40.9	60.9	45	83	56.4	58.3	20	93
PPV	90.3	81.3	69.2	53.8	52	23	24	70	44	21

PPV: Positive predictive value; OL: Overall lesion; AB: Active bleeding.