Table 3.

Clinical Implications and Costs Associated With Worst-Case BGM System Accuracy.

All	ISO 2003	ISO 2013	SAM	Increase in HbA1c (%)	Increase in SHE (cases PPY)	Additional cost (£ PPY)
(n = 43)				0.47	1.70	597
	No (n = 7)			0.47	1.70	597
	Yes (n = 36)			0.27	1.21	440
		No (n = 14)		0.24	1.21	440
		Yes (n = 22)		0.27	0.73	278
			No (n = 11)	0.27	0.73	278
			Yes (n = 11)	0.12	0.36	145

Table 3 represents the worst effect of inaccuracy within each set on HbA1c, incidence of SHE, and total additional cost. It is important to understand that the system leading to an increase in HbA1c of 0.47% is not the same as the one increasing the SHE by 1.70 cases PPY! The system leading to the highest additional cost of £597 may or may not be one of the two other systems (here, it is the system with worst effect on the SHE). In all but one case, the worst outcome in any of the groups is related to the worse of the two subgroups (eg, the highest additional cost of £278 among all systems who appeared to be ISO 15197:2013 compliant comes from a system falling into the ISO 2013/No SAM group).