Appendix I.

Example of calculation of sensitivity & specificity for HerpeSelect® based on Hawkins et al.

Index test (Focus)	Resolver test (WB)						Total
	Positive			Negative
	Kalon
	Positive	Negative	Total	Positive	Negative	Total
Positive	0.612	0.0681	0.680	0.045	0.075	0.120	0.800
Negative	0.000	0.011	0.011	0.000	0.189	0.189	0.200
Total	0.612	0.079	0.691	0.045	0.264	0.309	1.000

These steps were followed to calculate sensitivity and specificity for Focus ®:

Step 1. Using data from table 1 fill each of the cells. For example1, the value for this cell is calculated as 0.143 (proportion of samples with this result i.e. 30/210 HerpeSelect ® positive, Kalon ^™ negative) × 0.474 (proportion of these samples correctly resolved on WB. i.e. 9/19) = 0.680

Step 2. HerpeSelect ® sensitivity is total positive out of total i.e. 0.680/0.691 = 98.3%. Similarly, specificity is total negative out of total samples i.e.0.189/0.309=61.1%