OBJECTIVES: To describe methods used and successes realized in building the infrastructure to conduct pragmatic clinical trials of comparative effectiveness research (CER) in Washington State’s Learning Healthcare System - the Comparative Effectiveness Research Translation Network (CERTAIN).  METHODS: Leveraging the infrastructure of the Surgical Care and Outcomes Assessment Program (SCOAP), a statewide coordinated quality improvement program that tracks surgical outcomes in hospitals, we created an infrastructure for conducting CER/PCOR. We are using the CERTAIN network to conduct a pragmatic clinical trial – a multi-site, prospective, observational cohort study of patients in community settings with peripheral artery disease (PAD) treated with open surgical, endovascular, or conservatively managed care. Clinical and patient-reported outcomes (PRO) are collected at baseline, 30-days, 6- and 12-months post intervention. The primary outcome is the change in scores on the Walking Impairment Questionnaire. The SCOAP Medical Director engaged PAD-treating vascular surgeons, interventional radiologists and cardiologists. Study staff educated all institutional review boards about pragmatic trials. The SCOAP CERTAIN Survey Center administers all PRO surveys using a mode of administration of each patient’s choice (e.g. web-based, paper-pencil); and deploys vigorous follow-up contact algorithms to retain patients.  RESULTS: Over 18-months, 15 sites have been engaged and are enrolling patients. Over 5500 medical records have been screened; 1016 patients (18%) with PAD identified. 415/1,016 (41%) met all inclusion criteria and received enrollment packets, 193 are actively participating, 14 have completed the study. Enrollment continues through September 2013. In companion work, CERTAIN Investigators developed their own ‘symptom’ instrument, informed by interviews with 11 patients; and are conducting a sub-study to compare scores on PRO instruments administered using various modes of administration.  CONCLUSIONS: This CERTAIN PAD study illustrates the effort required to conduct a pragmatic trial. As the nation embraces the research paradigm of CER, Washington State’s Learning Healthcare System is modeling success.