Cochrane and the COMET initiative: developing the evidence base in oral medicine.

All clinicians in medicine and dentistry aim to deliver evidence-based practice; however, it is widely recognised that the current evidence base for interventions in oral medicine, as with many other specialties, is of a low quality. The highest level of evidence is considered to be the systematic review and meta-analysis. The Cochrane Collaboration and the Cochrane Oral Health group produce high quality systematic reviews, however, despite the large number of trials carried out for treatments in oral medicine, the results are often not able to be utilised to guide clinical care due to the various methodological limitations of the trials including the heterogeneity of outcome measures used. To improve the strength of the evidence base this will need to change. The Comet initiative aims to support the development of core outcome sets which are used to allow homogeneity of outcome measures in trials and therefore will allow pooling of data for meta-analysis in future systematic reviews. This paper explores the complexities involved in producing evidence for oral medicine interventions and introduces an approach for developing core outcome sets in oral medicine.