1. Division of Epidemiology, Mayo Clinic, Rochester, Minnesota4Dr Wang is now with the Division of Preventive Medicine, Wenzhou Medical University, Wenzhou, China.
2. Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, Minnesota
3. Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota
4. Division of Epidemiology, Mayo Clinic, Rochester, Minnesota