1. From the Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford (C.C.B., E.R.), the Centre for Trials Research (D.G., J.B., R.L., E.T.-J., K.H., N.K.), the Division of Population Medicine (R.P., G.N., N.A.F.), and Wales Centre for Primary and Emergency Research, School of Medicine (M.G.), Cardiff University, the Specialist Antimicrobial Chemotherapy Unit, Public Health Wales, University Hospital of Wales (M.W.), Cardiff, and the School of Population Health and Environment...