Current use of routinely collected health data to complement randomized controlled trials: a meta-epidemiological survey

Stanford Prevention Research Center, Department of Medicine (Hemkens, Ioannidis), Stanford University School of Medicine, Stanford, Calif.; Basel Institute for Clinical Epidemiology and Biostatistics (Hemkens), University Hospital Basel, Basel, Switzerland; Department of Pediatrics, Division of Infectious Diseases (Contopoulos-Ioannidis), Stanford University School of Medicine, Stanford, Calif.; Palo Alto Medical Foundation Research Institute (Contopoulos-Ioannidis), Palo Alto, Calif.; Department of Health Research and Policy (Ioannidis), Stanford University School of Medicine; Meta-Research Innovation Center at Stanford (METRICS) (Ioannidis), Stanford, Calif.

Stanford Prevention Research Center, Department of Medicine (Hemkens, Ioannidis), Stanford University School of Medicine, Stanford, Calif.; Basel Institute for Clinical Epidemiology and Biostatistics (Hemkens), University Hospital Basel, Basel, Switzerland; Department of Pediatrics, Division of Infectious Diseases (Contopoulos-Ioannidis), Stanford University School of Medicine, Stanford, Calif.; Palo Alto Medical Foundation Research Institute (Contopoulos-Ioannidis), Palo Alto, Calif.; Department of Health Research and Policy (Ioannidis), Stanford University School of Medicine; Meta-Research Innovation Center at Stanford (METRICS) (Ioannidis), Stanford, Calif.

Stanford Prevention Research Center, Department of Medicine (Hemkens, Ioannidis), Stanford University School of Medicine, Stanford, Calif.; Basel Institute for Clinical Epidemiology and Biostatistics (Hemkens), University Hospital Basel, Basel, Switzerland; Department of Pediatrics, Division of Infectious Diseases (Contopoulos-Ioannidis), Stanford University School of Medicine, Stanford, Calif.; Palo Alto Medical Foundation Research Institute (Contopoulos-Ioannidis), Palo Alto, Calif.; Department of Health Research and Policy (Ioannidis), Stanford University School of Medicine; Meta-Research Innovation Center at Stanford (METRICS) (Ioannidis), Stanford, Calif.