PLoS One 2014 16;9(10):e110248. Epub 2014 Oct 16.
Center for Injury Epidemiology, Liberty Mutual Research Institute for Safety, Hopkinton, Massachusetts, United States of America; Environmental and Occupational Medicine and Epidemiology Program, Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, United States of America; Department of Family Medicine and Community Health, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America.