Publication bias in otorhinolaryngology meta-analyses in 2021

One concern in meta-analyses is the presence of publication bias (PB) which leads to the dissemination of inflated results. In this study, we assessed how much the meta-analyses in the field of otorhinolaryngology in 2021 evaluated the presence of PB.

Six of the most influential journals in the field were selected. A search was conducted, and data were extracted from the included studies. In cases where PB was not assessed by the authors, we evaluated the risk of its presence by designing funnel plots and performing statistical tests.

Seventy-five systematic reviews were included. Fifty-one percent of them used at least one method for assessing the risk of PB, with the visual inspection of a funnel plot being the most frequent method used. Twenty-nine percent of the studies reported a high risk of PB presence. We replicated the results of 11 meta-analyses that did not assess the risk of PB and found that 63.6% were at high risk. We also found that a considerable proportion of the systematic reviews that found a high risk of PB did not take it into consideration when making conclusions and discussing their results.

Our results indicate that systematic reviews published in some of the most influential journals in the field do not implement enough measures in their search strategies to reduce the risk of PB, nor do they assess the risk of its presence or take the risk of its presence into consideration when inferring their results.