1. Department of Biostatistics School of Public Health, Southern Medical University Guangzhou China
2. Department of Medical Statistics School of Public Health, Sun Yat‐sen University Guangzhou China
3. Department of Epidemiology and Biostatistics School of Public Health, Xi'an Jiaotong University Health Science Center Xi'an China
4. Office of Biostatistics and Clinical Pharmacology The Center for Drug Evaluation, National Medical Products Administration Beijing China