Footnotes

• Handling editor Josef S Smolen

• Correction notice This article has been corrected since it published Online First. The first author's name has been corrected.

• Contributors LA and BT devised the project, the main conceptual ideas and proof outline, pooled and analysed data from the five randomised controlled trials (RCTs). AJ performed the statistical analysis. CP, XP, PC, CR, LG and BT designed and published the five RCTs involved in this article. LA and BT, wrote the manuscript. All authors discussed the results and contributed to the final manuscript.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests None declared.

• Patient consent for publication Not required.

• Provenance and peer review Not commissioned; externally peer reviewed.