- Correspondence to Dr Yihua Wu, Department of Epidemiology and Health Statistics, Zhejiang University School of Public Health, Hangzhou 310058, China; ; or Dr Jianting Cai, Department of Gastroenterology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China;
- Received August 14, 2014
- Revised September 4, 2014
- Accepted September 7, 2014
- First published September 19, 2014.
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