1. Department of Epidemiology, West Virginia University School of Public Health, Morgantown, West Virginia;
2. Health Science Center Libraries, University of Florida, Gainesville, Florida;
3. Department of Family Medicine, The Ohio State University College of Medicine, Columbus, Ohio;
4. West Virginia University College of Physical Activity and Sport Sciences, Morgantown, West Virginia;
5. Department of Biostatistics, West Virginia University School of Public Health, Morgantown, West Virginia;
6. Kaiser Permanente Washington Health Research Institute, Seattle, Washington