Methodological issues in newborn screening evaluation with special reference to congenital adrenal hyperplasia

Evidence-based evaluation of newborn screening is essential because of the increasing number of genetic tests, the mandatory nature of newborn screeni ng in the United States, and the growing cost to the public to maintain exp ensive screening programs, This paper discusses the methodological problems that arise when applying universally accepted criteria to disorders such a s congenital adrenal hyperplasia, These problems include the tendency of sc reening to alter the natural history of the disease, the lack of consensus about terms and definitions, and the paucity of longitudinal studies on scr een detected neonates, In order to evaluate and compare candidate screens w e recommend formal national trials of promising programs, with defined resp onsibility of state agencies, physicians, patients, and insurers for data s ubmission and analysis.