Quality performance of newborn screening systems: strategies for improvement.

Newborn metabolic screening is a public health activity with the potential to realize significant health gains for infants affected with a range of congenital conditions. Many of these are inborn errors of metabolism. The activities required to achieve the gains are diverse and carried out by a number of organizations, by families and by many health care professionals. Laboratories have the best-developed quality strategies, which include quality assurance programmes, guidelines, protocols and standards. Two-tier testing and use of multiple markers improve sensitivity and specificity. There are international initiatives to harmonize assay materials and definitions to allow better benchmarking between programmes. Outside the laboratory, standards, education and protocols improve the quality of specimen collection, diagnosis and treatment, which together produce the health gains.