In Reply The direct comparison between the 2008 study by Yang and colleagues1 and our study might not be appropriate due to different sampling strategies, methods of data collection, diagnostic procedures, and statistical analyses. In the 2008 study, a sample of 46 239 adults aged 20 years or older from only 14 provinces and municipalities was included. HbA1c level was not used to identify undiagnosed diabetes or prediabetes. Their calculations of standardized prevalence were weighted based on the Chinese population structure in 2006. Our study included 170 287 participants aged 18 years or older from 298 surveillance points covering all 31 provinces, autonomous regions, and municipalities in mainland China. The prevalence was standardized according to the Chinese population census in 2010.
Pei Gao, Xun Tang, Yonghua Hu. Prediabetes Prevalence in China—Reply. JAMA. 2017;318(16):1612–1613. doi:10.1001/jama.2017.13752