Table 3.

Estimated economic benefit flowing from the educational intervention

	Item	Data
A	Median values of monthly blood culture sets taken in ICU at pre-intervention	72
B	Estimated annual number of blood cultures at pre-intervention (A × 12)	864
C	Blood culture contamination rate at pre-intervention	9·5%
D	Estimated annual number of blood culture sets contaminated pre-intervention (B × C)	82
E	Estimated cost of one false-positive blood culture*	£5002
F	The estimated annual cost of contaminated blood culture at pre-intervention (D × E)	£410 164
G	Median values of monthly blood culture sets taken in ICU at post-intervention	72
H	Estimated annual number of blood cultures at post-intervention (G × 12)	864
I	Blood culture contamination rate at post-intervention	3·7%
J	Estimated annual number of blood culture sets contaminated at post-intervention of 3·7% (H × I)	32
K	Estimated annual cost of contaminated blood culture at post-intervention (J × E)	£160 064
L	Impact of intervention on the estimated annual cost savings due to reduction in blood culture contamination (3·7% from 9·5%; F–K)	£250 100

ICU, Intensive care unit.

^*Based on a previous study in Antrim Area Hospital [17].