We agree with Samara and Leucht that clinicians can feel overwhelmed by the vast quantity of published meta-analyses and variety of methodologies. It is therefore important that protocols for potential meta-analyses are published on open access repositories such as PROSPERO to reduce the risk of duplication. Unfortunately, we were unaware of the 2016 Samara et al meta-analysis at the time of conducting ours, as they did not register their protocol on PROSPERO, only including a protocol as a supplementary document at the time of publication.