Methodological issues in outcome studies of at-risk infants

Objective: To identify methodologic problems found in follow-up studies of infants at biologic and environmental risk and provide solutions and recommendations. Methods: This article is a literature review. Results: Problems fall into four groupings: (1) conceptualization/design issues, 2) subject population concerns, 3) procedural issues, and 4) measurement/outcome concerns. Conclusions: Main-effect models are not useful; confounding and mediating variables must be identified. In addition, the following are needed: alternative analytic techniques, more precise subject selection and characterization of risk factors, geographically defined samples, broadened scope of outcome measures, and use of epidemiologic techniques.