Measuring the benefits of screening for open neural tube defects.

Evaluation of the costs and benefits of public sector programmes is necessary to plan the optimum uses for society's resources. Here the benefits of screening for open neural tube defects are examined, and the most appropriate methodological approach to their valuation is discussed in the context of the possible provision by the National Health Service of a routine prenatal screening programme. It is argued that, in measuring the benefits of screening, previous evaluations have adopted an approach that is rather unsatisfactory from the standpoint of economic methodology. An attempt is therefore made here to show the effect that adopting a more appropriate approach would have on the estimated value of the benefit of routine screening. The effect is found to be a substantial increase in its estimated value.