Prevalence Rate of Multiple Chronic Conditions in Middle-aged and Elderly Chinese People from 2010 to 2019:a Meta-analysis 
WANG Meijie,ZHOU Xiang,LI Yajie,LIU Fangli,YAO Zhuoya
Chinese General Practice . 2021, (16): 2085 -2091 .  DOI: 10.12114/j.issn.1007-9572.2020.00.477