Contribution statement
OK had the initial idea for the study, performed the statistical analysis and wrote the first draft of the report. MEO and LVB performed the primary extraction of the data, and OK and AH supervised and harmonized the data extraction. SS helped with all issues concerning systematic review techniques. MR was the main contributor with respect to all clinical issues of this work. All authors contributed to data interpretation, discussion of findings and revision of the report, and have read and approved the final report. OK is the guarantor of this work and, as such, had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.