title: The Content of Statistical Requirements for Authors in Biomedical Research Journals.
abstract: BACKGROUND
  Robust statistical designing, sound statistical analysis, and standardized presentation are important to enhance the quality and transparency of biomedical research. This systematic review was conducted to summarize the statistical reporting requirements introduced by biomedical research journals with an impact factor of 10 or above so that researchers are able to give statistical issues' serious considerations not only at the stage of data analysis but also at the stage of methodological design.
  
  
  METHODS
  Detailed statistical instructions for authors were downloaded from the homepage of each of the included journals or obtained from the editors directly via email. Then, we described the types and numbers of statistical guidelines introduced by different press groups. Items of statistical reporting guideline as well as particular requirements were summarized in frequency, which were grouped into design, method of analysis, and presentation, respectively. Finally, updated statistical guidelines and particular requirements for improvement were summed up.
  
  
  RESULTS
  Totally, 21 of 23 press groups introduced at least one statistical guideline. More than half of press groups can update their statistical instruction for authors gradually relative to issues of new statistical reporting guidelines. In addition, 16 press groups, covering 44 journals, address particular statistical requirements. The most of the particular requirements focused on the performance of statistical analysis and transparency in statistical reporting, including "address issues relevant to research design, including participant flow diagram, eligibility criteria, and sample size estimation," and "statistical methods and the reasons."
  
  
  CONCLUSIONS
  Statistical requirements for authors are becoming increasingly perfected. Statistical requirements for authors remind researchers that they should make sufficient consideration not only in regards to statistical methods during the research design, but also standardized statistical reporting, which would be beneficial in providing stronger evidence and making a greater critical appraisal of evidence more accessible.
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Capital Medical University, Beijing 100069, China.
authors.forename: Tian-Yi
authors.initials: TY
authors.lastname: Liu
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Capital Medical University, Beijing 100069, China.
authors.forename: Si-Yu
authors.initials: SY
authors.lastname: Cai
authors.affiliation: Center of Clinical Epidemiology and Evidence-based Medicine, Beijing Children's Hospital, Capital Medical University, Beijing 100045, China.
authors.forename: Xiao-Lu
authors.initials: XL
authors.lastname: Nie
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Capital Medical University, Beijing 100069, China.
authors.forename: Ya-Qi
authors.initials: YQ
authors.lastname: Lyu
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Capital Medical University, Beijing 100069; Center of Clinical Epidemiology and Evidence-based Medicine, Beijing Children's Hospital, Capital Medical University, Beijing 100045, China.
authors.forename: Xiao-Xia
authors.initials: XX
authors.lastname: Peng
authors.affiliation: Center of Clinical Epidemiology and Evidence-based Medicine, Beijing Children's Hospital, Capital Medical University, Beijing 100045, China.
authors.forename: Guo-Shuang
authors.initials: GS
authors.lastname: Feng
mesh_terms: D015706:Bibliometrics; D035843:Biomedical Research; D019983:Guideline Adherence; D010506:Periodicals as Topic