1. Center for Quantitative Methods and Data Science, Institute for Clinical Research and Health Policy Studies, Tufts University School of Medicine, Boston, MA, USA
2. Johns Hopkins University Schools of Medicine, Baltimore, MD, USA
3. Centers for Disease Control and Prevention/Agency for Toxic Substances and Disease Registry, Office of Innovation and Analytics, National ALS Registry (CDC/ATSDR), Atlanta, GA, USA, and
4. ICF, Inc., Atlanta, GA, USA