The Developing Evidence to Inform Decisions about Effectiveness centers at the HMO Research Network Center for Education and Research on Therapeutics and the University of Pennsylvania are developing a design for a scalable distributed research network to support purposes related to therapeutics, including comparative effectiveness, safety, and utilization, and quality of care research. The project will implement a system prototype, conduct a proof-of-principle hypertension therapy research project, and make recommendations for expansion of the network.