RESUMEN
OBJECTIVE: To study how changes in law shape the public health system. DATA SOURCES: State newborn screening laws and the National Newborn Screening and Genetics Resource Center (NNSGRC). STUDY DESIGN: A time-series, quasi-experimental design spanning the years 1990-2006 for all states and the District of Columbia was conducted. Analysis proceeded using a multinomial logit with a dependent variable of whether agencies lagged behind, were on target with, or led their newborn screening law. Explanatory variables of three different types of limitations on agency discretion plus relevant controls were included in the model. DATA COLLECTION: State laws were coded for three types of discretion: whether an agency can choose a state's newborn screening panel conditions, whether an agency can charge and change newborn screening fees, and whether the agency can define their own newborn screening criteria. Each state's newborn screening law for each year in the dataset was coded with respect to the mandated number of conditions on a panel and compared with the NNSGRC dataset of actual newborn screening implemented in the state. PRINCIPAL FINDINGS: States that lack condition discretion have 6.02 greater odds of lagging behind newborn screening law, but the presence of criteria discretion results in 7.50 higher odds of lagging behind the law. Condition discretion and fiscal discretion are associated with successful implementation. The presence of criteria discretion is a barrier for successful implementation. CONCLUSIONS: Agency discretion can both hinder and facilitate program implementation. Thus, type of discretion determines implementation.