Samples in Research on Prenatal Cocaine Exposure: Vexing Problems and Practical Solutions

Abstract

Although research methodology in study of the effects of prenatal cocaine exposure has markedly Improved as this complex field has matured, there remain vexing methodological difficulties. Comparing findings across different cohort studies is challenging because of variations in how samples are described or because important sample characteristics are not documented. A few studies of prenatal poly-drug exposure with problems in sample design continue to be published, the implications of sample design for research questions need consideration, and sample attrition is a continuing problem. This paper explains these problems, and suggests some practical solutions. Examples are drawn from the current literature and the authors' experience with the Seattle Cocaine and Pregnancy Study, an early cohort study of cocaine effects.