A Practical Guide to Writing (and Understanding) a Scientific Paper: Meta-Analyses

Meta-analyses represent an unbiased way of summarising the evidence on a specific topic. A meta-analysis is a formal process for gathering and evaluating literature to answer a specific question, using statistics to combine the data from randomised controlled trials. However, their use is controversial, as there are several critical conditions and methodological considerations that could produce misleading conclusions. A wide and extensive systematic search, clear-cut inclusion criteria and appropriate data extraction are mandatory when it comes to obtaining all the evidence relating to the investigated topic. Statistical analyses should be performed carefully and all sources of heterogeneity should be explored to avoid dangerous bias. The design and the quality of the included studies should be clearly presented to show the reader the overall quality of the evidence that is presented in the meta-analysis. Finally, the results should be interpreted critically from both a clinical and a statistical point of view.