Characteristics that Predict Physician Participation in a Web-Based CME Activity: The MI-Plus Study - Schoen, Michael J.; Tipton, Edmond F.; Houston, Thomas K.; Funkhouser, Ellen; Levine, Deborah A.; Estrada, Carlos A.; Allison, Jeroan J.; Williams, O. Dale; Kiefe, Catarina I. (Journal of Continuing Education in the Health Professions, 2009)