参考文献/References:
原文获取处:URL: http://www.wjgnet.com/1007-9327/full/v21/i12/3679.htm
DOI: http://dx.doi.org/10.3748/wjg.v21.i12.3679
译者注:PRISMA:Preferred Reporting Items of Systematic reviews and Meta-Analyses。文献:Moher D, Liberati A, Tetzlaff J, Altman DG, The PRISMA Group (2009). Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement. Open Med, 2009, 3(3): 123-130. http://www.prisma-statement.org/Default.aspx
译者注:STROBE:strengthening the reporting of observational studies in epidemiology, 文献:History of STROBE. http://www.strobe-statement.org/history.html