Acupressure at the Neiguan P6 point for treating nausea and vomiting in early pregnancy: an evaluation of the literature

CRD COMMENTARY: The aims were stated, and the focus of the review was described in terms of the participants and interventions. The inclusion criteria were not defined in terms of study design or outcome. Three relevant databases were searched and the search terms were specified. However, there was no report of any language restrictions; there was no attempt to locate unpublished material, thus raising the possibility of publication bias; and there were no details provided on the methods used to select studies. The primary studies were not restricted by study design and validity was not formally assessed, though some aspects of validity were commented upon in the data extraction tables and in the text. Some relevant information on the primary studies was presented in tabular format but methods used to extract data were not described. A narrative review was appropriate given the heterogeneity among studies, but evidence from better quality studies was not highlighted. The discussion included consideration of the methodological flaws in the primary studies. The conclusions should be interpreted with caution given the methodological concerns expressed by the authors, and the lack of detail of the methods used to conduct the review.