Table 1

Comparison of yields and costs of strategy A (examination of a single section) with strategy B (routine levels)

	Yields			Costs*
Diagnostic category	Strategy A	Strategy B	Marginal yield	Strategy A	Strategy B	Marginal cost
*In Welcan units.
Normal	132	116		396	522
PALI	14	27	13	42	121.5
GCA	21	24	3	63	108
Total	167	167		501	751.5	250.5