Methods and criteria used in evidence-based decisions in public health

A workshop entitled, "The Impact of Maternal Thyroid Diseases on the Developing Fetus: Implications for Diagnosis, Treatment, and Screening," was held in Atlanta, Georgia, January 12-13, 2004. This paper reports on the session that examined methods and criteria used for decisions in public health. For this session the following papers were presented: "Methods to Evaluate Scientific Evidence," "Criteria for Screening," and "Public Health Considerations." Development of evidence-based guidelines, strengthened by rigorous systematic reviews, will improve the quality, efficiency, and cost effectiveness of management of thyroid dysfunction among reproductive-age women. Maternal and fetal benefits that have been hypothesized to result from screening pregnant and pre-pregnant women for hypothyroidism include reduced incidences of peripartum maternal complications and fetal loss and optimization of fetal and neonatal neuropsychological development. Screening should be considered as the initial step in a comprehensive program that includes appropriate diagnostic and therapeutic interventions. The actual benefits and potential risks (i.e., iatrogenic thyrotoxicosis) of implementing a thyroid function screening program have not been demonstrated in a prospective randomized clinical trial or prospective cohort study. Consequently, it is difficult to develop consensus and secure resources for a comprehensive thyroid function screening and therapeutic intervention program in women who are or anticipate becoming pregnant. Marshalling support for performance of both a clinical trial and high-quality observational studies should be a high priority.