Objective: The Americleft study is a North American initiative to undertake an intercenter outcome study for patients with repaired complete unilateral cleft lip and palate from five well-established North American cleft centers.
Design: Retrospective cohort study.
Setting: Five cleft palate centers in North America.
Methods: This is the first paper in a series of five that outlines the overall goals of the study and sets the basis for the clinical outcome studies that are reported in the following four papers. The five centers' samples and treatment protocols as well as the methods used for each study are reported. The challenges encountered and possible mechanisms to resolve them and reduce methodological error with intercenter studies are also reviewed.