Knowledge synthesis: How to improve the use of evidence from clinical trials?

Background The value of systematic reviews (SRs) is determined by methodology and reporting quality of primary studies and how the SR is conducted and reported. Aim This study discusses key aspects of clinical trials (CTs) that might affect the value of SRs. Design Narrative review. Results We highlighted the following CT factors that could affect SR value: Defining the purpose of CTs is important because it could directly impact whether an SR question is appropriately answered and formulated; choose the most appropriate intervention to answer a proposed SR question is critical because we can exclude or include different studies, directly influencing selection bias; when conducting SRs, the study's search must be restricted to equal or highly similar comparison groups, allowing suitable comparisons of the outcomes’ estimates; in SRs, it may be interesting to explore the effect of the most common definition of the disease used in clinical practice, being useful in evidence‐based dentistry and easily translated to daily practitioners; and deficiencies in CT reporting can lead to unusable reports, biased results, and conclusions. Conclusion All aspects discussed were found to be important for improving the use of evidence from CTs.