Screening for disease in the newborn: the evidence base for blood-spot screening.

This paper reviews the evidence of benefit resulting from newborn screening in Australia as well as for some of those disorders not yet included in the Australian panels, and discusses briefly disorders under active consideration for inclusion in the screening panels.There is solid evidence of benefit from newborn screening for phenylketonuria, congenital hypothyroidism, cystic fibrosis, and overall for the disorders included in tandem mass spectrometry screening. There is also some evidence of benefit for several disorders not screened for in Australia, including congenital adrenal hyperplasia. Harms resulting from screening include anxiety related to false positive results; adverse effects of unwarranted treatment for mild variants; unwanted genetic information; and the costs (opportunity costs) of screening. For well-run programs these harms are relatively small.Screening could become more effective with the development of good systems for rational consideration of disorders to be included, with the extended use of second tier testing to reduce the false positive rate, and with research on the most effective way to deal with mild variants. The most important aspect of increasing effectiveness is the full integration of the screening program, diagnostic laboratories, and the clinical service. This is already in place in Australasia.