An economic appraisal of the benefits of screening for open spina bifida.

Appraisal of the costs and benefits of public sector programmes is an essential part of planning the optimal allocation of society's resources. This paper reports a study of the potential benefits to be derived if the UK National Health Services (NHS) were to introduce a mass-screening programme for the prenatal detection of fetuses affected by open spina bifida. These benefits are compared with the costs of a screening programme as estimated in the Report [1] by the Working Group on Screening for Neural Tube Defects of the Department of Health and Social Security (DHSS), A satisfactory screening test for open spina bifida has been developed in recent years, but routine prenatal screening has not yet become generally available. The paper therefore considers first the inferences that may be drawn about the efficiency and desirability of implementing a national screening programme from comparison of its costs and benefits. A brief description of screening and its likely impact is followed by a discussion of previous attempts at measuring the benefits of a screening programme and it is argued that these evaluations have adopted an approach which is rather unsatisfactory from the standpoint of economic methodology. A more appropriate conceptual approach to measuring the benefits of a screening programme is outlined and, after discussing the resolution of the theoretical and practical problems encountered in applying it, estimates of the benefits are calculated. The findings are compared first with those of previous studies which are shown to have under-estimated the benefits and secondly with the costs of a screening programme which almost certainly are lower than the benefits. It is therefore concluded that a screening programme would constitute an efficient use of NHS resources. Details of the data and their sources are appended.