Table 2

Accuracy of haematological variables

Study		Year		Reference		Positive test definition		Incidence of sepsis		Sensitivity (%)	Specificity (%)	PPV (%)	NPV (%)	Positive LR (95% CI)	Negative LR (95% CI)
Study		Year		Reference		Positive test definition		Incidence of sepsis		Sensitivity (%)	Specificity (%)	PPV (%)	NPV (%)	Positive LR (95% CI)	Negative LR (95% CI)	Boyle	1978	12	Absolute neutrophil count ⩽5000/mm³	9/114	89	81	29	99	4.67 (2.96 to 7.37)	0.14 (0.02 to 0.87)
Boyle	1978	12	WCC <7000/mm³	9/114	78	96	64	98	20.42 (7.34 to 56.77)	0.23 (0.07 to 0.79)
Squire	1979	55	Abnormal band count (as referenced)	23/46	13	83	43	49	0.75 (0.19 to 2.98)	1.05 (0.82 to 1.35)
Squire	1979	55	Abnormal neutrophil count (as referenced)	23/46	61	83	78	68	3.50 (1.36 to 9.04)	0.47 (0.28 to 0.82)
Squire	1979	55	Platelet count <150 000/mm³	23/46	61	78	74	67	2.80 (1.21 to 6.50)	0.50 (0.29 to 0.87)
Squire	1979	55	WCC <500 or >24 000/mm³	23/46	44	96	91	63	10.00 (1.39 to 71.90)	0.59 (0.41 to 0.86)
Voora	1982	58	WCC <5000/mm³	9/59	22	98	67	88	11.11 (1.12 to 110.72)	0.79 (0.56 to 1.13)
King	1987	33	I:T ratio ⩾0.2	16/321	69	75	13	98	2.76 (1.88 to 4.05)	0.42 (0.20 to 0.86)
King	1987	33	WCC ⩽5000/mm³	16/340	44	96	37	97	11.81 (5.39 to 25.91)	0.58 (0.38 to 0.90)
Misra	1989	38	Band cell count	33/78					<10, LR = 0.36 (0.13 to 1.00)
									10–20, LR = 0.89 (0.52 to 1.51)
									>20, LR = 2.18 (1.14 to 4.18)
Misra	1989	38	I:T ratio ⩾2	33/78	90	73	71	92	3.41 (2.08 to 5.60)	0.12 (0.04 to 0.37)
Misra	1989	38	Platelet count (per mm³)	33/78					<1, LR = 4.08 (0.17 to 96.95)
									1–1.5, LR = 1.48 (0.78 to 2.81)
									>1.5, LR = 0.79 (0.56 to 1.10)
Misra	1989	38	WCC (per mm³)	33/78					<5000, LR = 2.96 (1.25 to 6.96)
									5–15 000, LR = 0.64 (0.45 to 0.92)
									>15 000, LR = 1.36 (0.29 to 6.34)
Seibert	1990	52	WCC <5000 or >20 000/mm³ or I:T ratio ⩾0.2 (early infection)	Not given^2-151	63	68	11	96	2.0^2-151	0.54^2-151
Seibert	1990	52	WCC <5000 or >20 000/mm³ or I:T ratio ⩾0.2 (late infection)	Not given^2-151	33	61	26	80	0.9^2-151	1.10^2-151
Bonadio	1991	11	Neutropenia <1500/mm³	80/1000	1	93	1	92	0.17 (0.02 to 1.18)	1.07 (1.04 to 1.10)
Krediet	1992	35	I:T ratio ⩾0.2 (early infection)	14/49	86	51	41	90	1.77 (1.18 to 2.64)	0.28 (0.07 to 1.04)
Krediet	1992	35	I:T ratio ⩾0.2 (late infection)	25/48	68	65	68	65	1.96 (1.05 to 3.64)	0.49 (0.26 to 0.94)
Peakman	1992	39	Neutrophil count <2000 or >7500/mm³	17/42	29	64	36	57	0.82 (0.33 to 2.02)	1.10 (0.72 to 1.69)
Peakman	1992	39	Platelet count <150 000/mm³	17/42	6	84	20	57	0.39 (0.05 to 3.01)	1.12 (0.91 to 1.38)
Peakman	1992	39	WCC <5000 or >20 000/mm³	17/42	18	76	33	58	0.74 (0.21 to 2.55)	1.08 (0.79 to 1.48)
Hiew	1992	31	I:T ratio >0.2	30/70	13	84	27	69	0.85 (0.29 to 2.45)	1.03 (0.87 to 1.22)
Hiew	1992	31	Neutrophil count ⩽1000 or ⩾5400–14 400/mm³ (age dependent)	30/70	53	44	29	69	0.96 (0.65 to 1.42)	1.05 (0.66 to 1.68)
Hiew	1992	31	Platelet count <150 000/mm³	30/70	3	94	20	70	0.58 (0.07 to 5.00)	1.03 (0.94 to 1.12)
Hiew	1992	31	WCC <5000 or >21 000, 30 000, 150 000/mm³ (age dependent)	30/70	27	81	38	72	1.44 (0.67 to 3.10)	0.90 (0.71 to 1.15)
DaSilva	1994	18	Band cell count >1000/mm³	28/147	50	91	56	89	5.41 (2.76 to 10.61)	0.55 (0.38 to 0.80)
DaSilva	1994	18	I:T ratio ⩾0.2	28/147	18	96	50	83	4.25 (1.32 to 13.68)	0.86 (0.72 to 1.02)
DaSilva	1994	18	WCC ⩾20 000 or ⩽5000/mm³	28/147	36	80	29	84	1.77 (0.96 to 3.26)	0.81 (0.60 to 1.08)
Philip	1994	40	I:T ratio >0.2	32/311	53	82	25	94	2.91 (1.93 to 4.38)	0.57 (0.40 to 0.83)

↵2-151 The data presented in this report did not allow 2 × 2 tables to be created. It is not therefore possible to calculate the incidence of infection or confidence intervals around the likelihood ratios. CI = confidence interval; I:T ratio = immature/total white cell count; LR = likelihood ratio; NPV = negative predictive value; PPV = positive predictive value; WCC = white cell count.