Erratum

Since the publication of this article [1], we have been made aware that the declaration of the competing interests of one of the authors was omitted. The ‘Competing interests’ section should have read as follows:

“Richard Brady is the owner of researchactive.com Ltd., a company that provides websites, and develops app and social media solutions for the health care market. No external company was involved in the drafting, editing or analysis within this paper.”