The primary goal of this project is to expand the research capabilities of the existing clinical research network, the CFAR Network of Integrated Clinic Systems (CNICS). This will be accomplished by developing technical and analytic tools to import HIV resistance data directly from clinical laboratories into the electronic medical record (EMR) at the network's clinical sites. At the clinical sites the data is used for clinical care and then transferred into the network's central data repository. The focus of this project is to extend and apply new technologies to an existing research network by developing standard for the automatic download of viral resistance data into EMRs, to organize the data for clinical decision making, to populate the research network's central data repository and utilize analytic strategies and statistical methodology to define the effect of cumulative HIV resistance on the pace of development on disease progression. The CNICS research network data system exists to receive, organize, store, retrieve and analyze securely transferred clinical data from electronic medical records at sites dedicated to HIV care and research. Many studies have evaluated antiretroviral treatment failure and the importance of HIV resistance, however the role of resistance in predicting the progression of HIV clinical disease has not been determined. In this application we focus on adding the new data elements of viral resistance to the CNICS research network