| Newborn screening for inborn errors of metabolism (IEM) can help prevent or reduce mortality and morbidity through timely identification and subsequent treatment. North Carolina (NC) uses tandem mass spectrometry to screen newborns for over 25 IEM. This dissertation is divided into three parts. The first part examined follow-up procedures and compliance in submitting a repeat screen among NC newborns with a borderline abnormal initial newborn screening result. Data was drawn from linking newborn screening records with birth certificate, census and health professions data. No repeat screen was submitted for approximately 9% of these infants. Using logistic regression analysis adjusted for clustering, infants who were Hispanic, black, living in a neighborhood with a low socio-economic index, and whose families did not receive a sent notification letter were less likely to have a repeat screen submitted. The second part surveyed pediatricians of the NC Pediatric Society to explore pediatricians' knowledge of NC newborn screening policies, their clinical protocol for handling results and their personal beliefs about the utility of newborn screening. About half of participants ranked themselves in the lower ranges of level of knowledge and comfort in communicating screening results. Only 57% of pediatricians correctly answered over half of the questions relating to newborn screening and state policies. Among those in clinical practice, 15% of pediatricians assumed that results were normal when they had not received a screening result and 32% did not provide families with normal screening results. The third part examined risk factors for transient neonatal tyrosinemia (TNT), abnormal elevations in tyrosine during the neonatal period that resolve in time. Using logistic regression analysis, infants who were premature, small-for-gestational-age, breast-fed or Hispanic were found to be at higher risk for TNT. Overall, these findings suggest that: (1) follow-up strategies need to address ways to improve rates of repeat screen submission, (2) further education is needed for pediatricians about newborn screening and its related policies, and (3) the number of false positive screens for inborn errors of tyrosine metabolism may be reduced by the consideration of gestational age, type of feeding and ethnic group. |
