The objective of the American Academy for Cerebral Palsy and Developmental Medicine (AACPDM) evidence reports is to provide the biomedical research and clinical practice communities with the current state of evidence about various interventions for the management of developmental disabilities. The AACPDM evidence reports aggregate all that has been published about outcomes of an intervention for a medical condition, gauge the credibility (i.e. strength of the internal validity) of that evidence, and identify gaps in our scientific knowledge. Methodology for developing and procedures for approving these systematic reviews can be found on the internet at www.aacpdm.org in the AACPDM Database of Evidence Reports, which contains initial and updated reports.