1. Division of Pulmonary, Allergy, and Critical Care Medicine
2. Department of Biomedical Data ScienceStanford UniversityStanford, California
3. Division of Pulmonary and Critical Care MedicineUniversity of VirginiaCharlottesville, Virginia
4. Division of Pulmonary and Critical Care Medicine
5. Department of EpidemiologyUniversity of MichiganAnn Arbor, Michigan