A post-publication investigation conducted by the Elsevier's Research Integrity & Publishing Ethics team on behalf of the journal could not confirm whether or not ethical approval was given specifically for the research presented in this publication in line with the journal's policy. It has come to our attention that the same ethics approval number appears to have been used for other studies in different publications, raising concerns about the appropriateness of the approval reported for this study.
A Sun, study studied this question.