The Food and Drug Administration (FDA) has issued a document “Evaluating the Effectiveness of Anticoccidial Drugs in Food-Producing Animals” that provides guidance for designing and conducting clinical effectiveness studies.  The document also describes criteria the Center for Veterinary Medicine  believes are the most appropriate for the evaluation of the effectiveness of anticoccidial drugs intended for use in poultry and other food-producing animals.  The November 20, 2012 Federal Register notice is available here.