Table 4.

 AUCs (95% CI) for the discrimination of patients with bacteraemia from those without bacteraemia

Age	Lymphocytopenia	Neutrophilia	Raised total WBC
<50	0.69 (0.66 to 0.72)	0.56 (0.53 to 0.59)**	0.52 (0.49 to 0.55)**
50–69	0.67 (0.64 to 0.70)	0.63 (0.60 to 0.68)*	0.59 (0.56 to 0.63)*
70–79	0.69 (0.67 to 0.71)	0.67 (0.65 to 0.70)	0.65 (0.62 to 0.67)*
>80	0.68 (0.66 to 0.70)	0.63 (0.61 to 0.66)**	0.62 (0.60 to 0.64)**
All cases	0.69 (0.67 to 0.72)	0.63 (0.61 to 0.66)**	0.60 (0.57 to 0.62)**

WBC components predicting bacteraemia stratified by age. AUCs were calculated for different age groups, comparing the ability of lymphocytopenia, neutrophilia, and raised total WBC to discriminate patients with bacteraemia from those without. Higher AUCs indicate better discrimination. Comparisons were made between the lymphocytopenia AUCs and neutrophilia or WBC AUCs. *p<0.05; **p<0.01 (comparisons made by Z testing).

AUC, area under the receiver operator characteristic plot; CI, confidence interval; WBC, white blood cell count.