PIER is a product of ACP, The American College of Physicians and is a web-based authoritative, evidence-based guidance tool. PIER's disease modules include sections on diagnosis, prevention, screening, drug therapy, patient education and case scenarios. On the PDA application, topics are supported with tables, and references to Web sites for supporting articles in Annals of Internal Medicine and PubMed. PIER adds and revises information as new disease findings become available.