Background: From 2005 to 2010, we conducted 2 randomized studies on a journal (Medicina Clínica), where we took manuscripts received for publication and randomly assigned them to either the standard editorial process or to additional processes. Both studies were based on the use of methodological reviewers and reporting guidelines (RG). Those interventions slightly improved the items reported on the Manuscript Quality Assessment Instrument (MQAI), which assesses the quality of the research report. However, masked evaluators were able to guess the allocated group in 62% (56/90) of the papers, thus presenting a risk of detection bias. In this post-hoc study, we analyse whether those interventions that were originally designed for improving the completeness of manuscript reporting may have had an effect on the number of citations, which is the measured outcome that we used. Methods: Masked to the intervention group, one of us used the Web of Science (WoS) to quantify the number of citations that the participating manuscripts received up December 2016. We calculated the mean citation ratio between intervention arms and then quantified the uncertainty of it by means of the Jackknife method, which avoids assumptions about the distribution shape. Results: Our study included 191 articles (99 and 92, respectively) from the two previous studies, which all together received 1336 citations. In both studies, the groups subjected to additional processes showed higher averages, standard deviations and annual rates. The intervention effect was similar in both studies, with a combined estimate of a 43% (95% CI: 3 to 98%) increase in the number of citations. Conclusions: We interpret that those effects are driven mainly by introducing into the editorial process a senior methodologist to find missing RG items. Those results are promising, but not definitive due to the exploratory nature of the study and some important caveats such as: the limitations of using the number of citations as a measure of scientific impact; and the fact that our study is based on a single journal. We invite journals to perform their own studies to ascertain whether or not scientific repercussion is increased by adhering to reporting guidelines and further involving statisticians in the editorial process.

DGA, JAG and EC belong to MiRoR (Methods in Research on Research), which has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 676207. EC and JC are partially supported by the grants MTM2015–64465-C2–1-R (MINECO/FEDER, UE) from the Secretaría de Estado de Investigación, Desarrollo e Innovación del Ministerio de Economía y Competitividad (Spain) and through grant 2017 SGR 622 from the Departament d’Economia i Coneixement de la Generalitat de Catalunya (Spain). The funding bodies had no role in the study design, data collection and analysis, results interpretation, or in writing the manuscript.