Correction

Following publication of the original article [1], the author report typographical errors in the

Figure 1 Study Search Strategy and Review Process – the lowest box on the right hand side should read “Full-texts excluded with reasons (n=37)” instead of “(n=38)”

Page 3 of the text, column 2, paragraph 2, second-last sentence should be “Subsequently 71 records were included for full review and 37 excluded” instead of “Subsequently 70 records were included for full review and 38 excluded”