The objective of this study was to evaluate economically a screening programme 
within the Oxford Regional Health Authority for Down's syndrome, based on 
maternal serum alpha fetoprotein, unconjugated oestriol and human chorionic 
gonadotrophin as well as maternal age (the triple test) against maternal age 
alone. The design of the study involved cost-effectiveness analysis of the 
triple test relative to the maternal age screening programme, and the main 
outcome measure was the cost per Down's birth avoided. It was found that the 
triple test is more cost-effective over a wide range of assumptions concerning 
detection rates and procedure costs. Indirect costs are important in considering 
the cost-effectiveness of the screening programmes. The most efficient detection 
rate is around 58 per cent for which the cost per Down's birth avoided is 
approximately 29,600 pounds if only direct costs are evaluated, 20,100 pounds if 
all NHS costs are considered and -49,800 pounds if all resource consequences are 
analysed. It may be concluded that screening for Down's syndrome using the 
triple test is cost-effective over a wide range of assumptions concerning 
detection rate and procedure costs. If all resource costs are considered, the 
programme is highly cost-effective in comparison with other health care 
interventions.