Contributors should provide a description of what each of them contributed to the manuscript.

The description should be divided in following categories, as applicable:
concepts, design, the definition of intellectual content, literature search, clinical studies, experimental studies, data acquisition, data analysis, statistical analysis, manuscript preparation, manuscript editing, and manuscript review. The authors' contributions will be printed on the first page of the article. One or more author should take responsibility for the integrity of the work as a whole from inception to published article and should be designated as 'guarantor'.