Table 6 .

Diagnostic performance of rectal bleeding in diagnosis of colorectal cancer

Index test and setting	TP	FP	FN	TN	Sensitivity (95% CI)	Specificity (95% CI)	Risk with positive test result (95% CI)	Risk with negative test result (95% CI)
Rectal bleeding, secondary care
Bafandeh 2008	4	138	12	326	0.25 (0.07 to 0.52)	0.70 (0.66 to 0.74)	0.03 (0.01 to 0.07)	0.04 (0.02 to 0.06)
Bjerregaard 2007	83	1090	39	960	0.68 (0.59 to 0.76)	0.47 (0.45 to 0.49)	0.07 (0.06 to 0.09)	0.04 (0.03 to 0.05)
Brewster 1994	9	150	12	291	0.43 (0.22 to 0.66)	0.66 (0.61 to 0.70)	0.06 (0.03 to 0.11)	0.04 (0.02 to 0.07)
Farrands 1995	5	62	8	64	0.39 (0.14 to 0.68)	0.51 (0.42 to 0.60)	0.08 (0.03 to 0.17)	0.11 (0.05 to 0.21)
Panzuto 2003	18	96	23	143	0.44 (0.29 to 0.60)	0.60 (0.53 to 0.66)	0.16 (0.10 to 0.24)	0.14 (0.09 to 0.20)
Selvachandran 2002	82	1505	13	668	0.86 (0.78 to 0.93)	0.31 (0.29 to 0.33)	0.05 (0.04 to 0.06)	0.02 (0.01 to 0.03)
Steine 1994	17	271	37	1498	0.32 (0.20 to 0.46)	0.85 (0.83 to 0.86)	0.06 (0.04 to 0.09)	0.02 (0.02 to 0.03)
Tan 2002	33	121	25	306	0.57 (0.43 to 0.70)	0.72 (0.67 to 0.76)	0.21 (0.15 to 0.29)	0.08 (0.05 to 0.11)
Tate 1988	9	40	5	76	0.64 (0.35 to 0.87)	0.66 (0.56 to 0.74)	0.18 (0.09 to 0.32)	0.06 (0.02 to 0.14)
Thompson 2007	333	5079	134	2983	0.71 (0.67 to 0.75)	0.37 (0.36 to 0.38)	0.06 (0.06 to 0.07)	0.04 (0.04 to 0.05)
Thompson 2008	624	9841	322	5646	0.66 (0.63 to 0.69)	0.37 (0.36 to 0.37)	0.06 (0.06 to 0.06)	0.05 (0.05 to 0.06)
Zarchy 1991	8	222	15	549	0.35 (0.16 to 0.57)	0.71 (0.68 to 0.74)	0.04 (0.02 to 0.07)	0.03 (0.02 to 0.04)
Rectal bleeding as only symptom, secondary care
Thompson 2008	105	4128	841	11 359	0.11 (0.09 to 0.13)	0.73 (0.73 to 0.74)	0.02 (0.02 to 0.03)	0.07 (0.07 to 0.07)
All constipated, bleeding overt, secondary care
Pepin 2002	2	66	6	489	0.25 (0.03 to 0.65)	0.88 (0.85 to 0.91)	0.03 (0.00 to 0.10)	0.01 (0.00 to 0.03)
All bleeding, dark blood, primary care
Ellis 2005	3	28	8	191	0.27 (0.06 to 0.61)	0.87 (0.82 to 0.91)	0.10 (0.02 to 0.26)	0.04 (0.02 to 0.08)
Mant 1989	4	19	12	109	0.25 (0.07 to 0.52)	0.85 (0.78 to 0.91)	0.17 (0.05 to 0.39)	0.10 (0.05 to 0.17)
Metcalf 1996	3	28	5	63	0.38 (0.09 to 0.76)	0.69 (0.59 to 0.79)	0.10 (0.02 to 0.26)	0.07 (0.02 to 0.16)
Robertson 2006	9	112	13	470	0.41 (0.21 to 0.64)	0.81 (0.77 to 0.84)	0.07 (0.04 to 0.14)	0.03 (0.01 to 0.05)
All bleeding, dark blood, secondary care
Bjerregaard 2007	29	114	54	976	0.35 (0.25 to 0.46)	0.90 (0.88 to 0.91)	0.20 (0.14 to 0.28)	0.05 (0.04 to 0.07)
All bleeding, first episode, primary care
Ellis 2005	5	101	6	154	0.46 (0.17 to 0.77)	0.60 (0.54 to 0.66)	0.05 (0.02 to 0.11)	0.04 (0.01 to 0.08)
Fijten 1995	9	164	0	96	1.00 (0.66 to 1.00)	0.37 (0.31 to 0.43)	0.05 (0.02 to 0.10)	0.00 (0.00 to 0.04)
Norrelund 1996	45	271	9	39	0.83 (0.71 to 0.92)	0.13 (0.09 to 0.17)	0.14 (0.11 to 0.19)	0.19 (0.09 to 0.33)
All bleeding, mixed with stool, primary care
Ellis 2005	1	32	10	223	0.09 (0.00 to 0.41)	0.88 (0.83 to 0.91)	0.03 (0.00 to 0.16)	0.04 (0.02 to 0.08)
Metcalf 1996	5	41	3	50	0.63 (0.25 to 0.92)	0.55 (0.44 to 0.65)	0.11 (0.04 to 0.24)	0.06 (0.01 to 0.16)
Robertson 2006	17	297	5	285	0.77 (0.55 to 0.92)	0.49 (0.45 to 0.53)	0.05 (0.03 to 0.09)	0.02 (0.01 to 0.04)
All bleeding, solely mixed with stool, primary care
Fijten 1995	2	12	3	227	0.40 (0.05 to 0.85)	0.95 (0.91 to 0.97)	0.14 (0.02 to 0.43)	0.01 (0.00 to 0.04)
All bleeding, on paper only, primary care
Ellis 2005	2	80	9	175	0.18 (0.02 to 0.52)	0.69 (0.63 to 0.74)	0.02 (0.00 to 0.09)	0.05 (0.02 to 0.09)
Mant 1989	5	47	10	75	0.33 (0.12 to 0.62)	0.62 (0.52 to 0.70)	0.10 (0.03 to 0.21)	0.12 (0.06 to 0.21)
Metcalf 1996	2	22	6	69	0.25 (0.03 to 0.65)	0.76 (0.66 to 0.84)	0.08 (0.01 to 0.27)	0.08 (0.03 to 0.17)

TP=true positives; FP=false positives; FN=false negatives; TN=true negatives.