Clinical research promotes development of nephrology in China: an analysis of 20 years of scientific publications.

Background: To study the trend of clinical and basic research output in the field of nephrology in China during the past 20 years. Methods: The journals listed in the "Urology and Nephrology" category of Science Citation Index Expanded (SCIE) subject categories were selected. The papers were retrieved by searching the PubMed database. Mainland China (ML), Hong Kong (HK), and Taiwan (TW) were chosen as investigative regions compared with other developed countries. Geographical difference in publications in ML was analyzed. The change between clinical and basic research papers was compared. The accumulated or average impact factor (IF) and the number of papers published in the 10 most impacted journals were calculated to determine the quality of papers. Results: The research output in the field of nephrology in ML developed markedly in the last 7 years (an average annual increase of 54% from 2004); ML exceeded TW and HK since 2008. The research output born in ML was mainly from five cities, for example, Beijing, Shanghai, Nanjing, Guangzhou, and Hangzhou, which accounted for 72% of the total. Since 2001, clinical research papers increased yearly by 11.55, and the basic research papers increased by 4.55. However, clinical trials were still limited. In 2010, ML had the highest accumulated IF and the lowest average IF. ML had the second highest number of publications in the 10 top-ranking nephrology journals among the three regions. Conclusions: China has made a remarkable progress in the field of nephrology. Clinical researches have promoted the development of nephrology. The quality of research papers in China needs further improvement.