Table 4.

Number of districts in which universal screening would be cost effective compared with selective screening according to rates of uptake of testing, pretest discussion time, and test costs and assuming willingness to pay £10 000 per additional life year gained

Length of pretest discussion (min)	No of districts
	Test costs in London (16 districts)			Test costs outside London (102 districts)
	£2.70	£15.00		£0.60	£2.70
Universal uptake 95%, selective uptake 20%
0	16	14		102	72
1	16	13		102	71
2	16	13		100	61
4	16	13		95	50
6	16	13		82	39
Universal uptake 95%, selective uptake 60%
0	16	13		102	35
1	16	13		102	27
2	16	13		100	22
4	16	13		80	17
6	16	12		55	14
Universal uptake 50%, selective uptake 20%
0	16	13		102	61
1	16	13		100	47
2	16	13		92	37
4	16	13		66	21
6	16	13		38	17
Universal uptake 50%, selective uptake 60%
0	0	0		0	0
1	0	0		0	0
2	0	0		0	0
4	0	0		0	0
6	0	0		0	0