Marguerite Koster


Senior Manager, Department of Clinical Analysis, Evidence-Based Medicine Services Unit, Kaiser Permanente Southern California


Marguerite Koster, MA, MFT is the Senior Manager of the Evidence-Based Medicine Services Unit within the Southern California Permanente Medical Group, a partnership of physicians which contracts exclusively with the nonprofit Kaiser Foundation Health Plan to provide medical services for more than 4.2 million members in Kaiser Permanente’s Southern California Region. In this position, she manages a staff of 11 evidence specialists who systematically review and critically appraise scientific evidence in support of Kaiser Permanente’s clinical practice guideline, medical technology assessment, and health system implementation programs.

Ms. Koster was recently appointed to the Cochrane Steering Group (CSG), as one of its first two external members. She is also the Immediate Past Chair of the Guidelines International Network/North America (G-I-N/NA) community, as well as a member of the Guidelines International Network. In addition, she has served on expert panels for The Joint Commission (Osteoporosis) and the Patient-Centered Outcomes Research Institute, including the PCORI Dissemination and Implementation Toolkit, Integrating Multiple Data Sources for Meta-Analysis to Improve Patient-Centered Outcomes Research (MUDS); and By Consumers, for Consumers: Building Capacity and Partnerships to Enhance Patient-centeredness.