Update on the methods of the U.S. Preventive Services Task Force: insufficient evidence.Petitti DB, Teutsch SM, Barton MB, Sawaya GF, Ockene JK, DeWitt T; U.S. Preventive Services Task Force. Ann Intern Med. 2009 Feb 3;150(3):199-205. The U.S. Preventive Services Task Force (USPSTF) seeks to provide reliable and accurate evidence-based recommendations to primary care clinicians. However, clinicians indicate frustration with the lack of guidance provided by the USPSTF when the evidence is insufficient to make a recommendation. This article describes a new USPSTF plan to commission its Evidence-based Practice Centers to collect information in 4 domains pertinent to clinical decisions about prevention and to report this information routinely. The 4 domains are potential preventable burden, potential harm of the intervention, costs (both monetary and opportunity), and current practice. The process and rationale used to select these domains are presented, along with examples of how clinicians might use the information to guide clinical decision making when evidence is insufficient.