Author Contribution
All authors contributed to the design of the study. EW, CR, AAP, CJJ and JG contributed to article selection and data extraction. EW, CR and JG conducted the analyses and wrote the initial draft of the manuscript. All authors contributed to the interpretation of the data, revised the manuscript and approved the final version.
Figure 1. STROBE checklist response rates by paper section and study design using a conservative or liberal scoring.