Footnotes

• Contributors RP and TRF identified the paper of interest. TRF wrote the first draft. RP added the verdict. Both authors edited and approved the final version.

• 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 Both TRF and RP are authors of several Systematic Reviews and have received research funding from the UK NIHR, the MRC, the BHF and Wellcome to carry out some of these reviews. RP has received grants from the UK NIHR, Cancer Research UK, BHF, NIHR School of Primary Care Research and support from the NIHR Oxford Biomedical Research Centre and the NIHR Community Healthcare MedTech and In Vitro Diagnostics Co-operative.

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

• Patient consent for publication Not required.