Search strategy
The following databases will be searched:
These databases will be searched for entries between the period of 1st October 2012 to the 31st May 2021. This aligns with the end date of the search entries used in a previous systematic review on the same subject11. Studies which were published earlier and included in the previous systematic review will be evaluated for inclusion in the current systematic review.
Forward and backward citation analysis will be used in all included studies to pinpoint other relevant studies. Any additional studies discovered by the review team who are experts in the field may be included. Only published, peer-reviewed full reports will be included.