: The HMO Research Network CERT has provided important insights into the use, safety and effectiveness of therapies and requests funding to continue leveraging populations from a collaboration of diverse health plans as generalizable sources of therapeutics evidence and as vehicles for disseminating and implementing therapeutics best practices. Our sub-theme will be post-marketing safety, although we will also continue to be active in promoting physician and patient behavior change, the uses of information technology, and health policy to optimize the use of therapeutics. The HMORN CERT's core will consist of 13 health plans of the HMO Research Network, with total membership of 11 million. All have public domain research units strongly linked to their plans'senior leadership and delivery systems. The HMORN CERT will use a Virtual Data Warehouse to facilitate use of enrollment, pharmacy, diagnosis and procedure data, which provides the highest level of patient privacy while facilitating complex multi-site studies. All sites are also implementing electronic medical records, allowing a greater range of studies. The CERT will focus on studies requiring detailed data and/or the ability to engage providers and plan members. It will also provide critical infrastructure support for ongoing DEcIDE (AHRQ) and FDA contracts, and collaborate with the NCI-funded HMORN Cancer Research Network and NIH-funded Clinical Translational Science Centers. New core studies will include both substantive and methodological work: 1) longitudinal study of the safety and efficacy of drug-eluting coronary artery stents;2) testing new methods for rapid prospective drug safety assessment by using routinely collected electronic health data;3) use and safety of antipsychotic medications in children, focusing on abnormalities of glycemic control, and 4) risk of serious infection with use of new biological agents for rheumatoid arthritis in the elderly. These will be complemented by additional activities, including targeted collaborations with other CERTs. New activities will include: 1) A Health Plan Consortium for Public Health, involving larger health plans, to perform drug/vaccine safety studies requiring populations of tens of millions;2) Studies impacting Medicare &Medicaid populations;3) An Institute for Clinical and Economic Review to facilitate dissemination of cost effective therapies by informing rational coverage decisions;and 4) Education and dissemination programs.