Quality of evidence matters: is it well reported and interpreted in infertility journals?

To evaluate if the authors of published systematic reviews (SRs) reported the level of quality of evidence (QoE) in the top 5 impact factor infertility journals and to analyze if they used an appropriate wording to describe it.

This is a cross-sectional study. We searched in PubMed for SRs published in 2017 in the five infertility journals with the highest impact factor. We analyzed the proportion of SRs published in the top 5 impact factor infertility journals that reported the SRs' QoE, and the proportion of those SRs in which authors used consistent wording to describe QoE and magnitude of effect.

The QoE was reported in only 21.4% of the 42 included SRs and in less than 10% of the abstracts. Although we did not find important differences in the report of QoE of those that showed statistically significant differences or not, p value was associated with the wording chosen by the authors. We found inconsistent reporting of the size the effect estimate in 54.8% (23/42) and in the level of QoE in 92.9% (39/42). Whereas the effect size was more consistently expressed in studies with statistically significant findings, QoE was better expressed in those cases in which the p value was over 0.05.

We found that in 2017, less than 25% of the authors reported the overall QoE when publishing SRs. Authors focused more on statistical significance as a binary concept than on methodological limitations like study design, imprecision, indirectness, inconsistency, and publication bias. Authors should make efforts to report the QoE and interpret results accordingly.