About the Authors

Guanghui Jin

Affiliation Department of General Practice, School of General Practice and Continuing Education, Capital Medical University, Beijing, P. R. China

Yali Zhao

Affiliation Department of General Practice, School of General Practice and Continuing Education, Capital Medical University, Beijing, P. R. China

Chao Chen

Affiliation Department of General Practice, School of General Practice and Continuing Education, Capital Medical University, Beijing, P. R. China

Wenji Wang

Affiliation Puren Hospital, Beijing, P. R. China

Juan Du

Affiliation Department of General Practice, School of General Practice and Continuing Education, Capital Medical University, Beijing, P. R. China

Xiaoqin Lu

xq6518@163.com

Affiliation Department of General Practice, School of General Practice and Continuing Education, Capital Medical University, Beijing, P. R. China

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: GHJ XQL YLZ. Performed the experiments: GHJ CC WJW. Analyzed the data: GHJ. Contributed reagents/materials/analysis tools: GHJ XQL JD. Wrote the paper: GHJ YLZ XQL.