Is the trend to publish reviews and clinical trials related to the journal impact factor? Analysis in dentistry field.

It is generally accepted that the Journal Impact Factor is a quality criterion. The objective was to determine the evolution along the period 2010-2016 of number of different types of papers, reviews and clinical trials, published by dental journals, as well as if they are related with the quartile occupied in the Journal Impact Factor 2017 ranking. To this end, ten journals per quartile belonging to the field Dentistry, Oral Surgery and Medicine in the 2017 Journal Citation Reports were randomly selected. For each journal and year, the total number of narrative reviews, systematic reviews (with and without meta-analysis), meta-analysis, clinical trials and randomized controlled trials were obtained from Pubmed. To achieve our goal, the slope of these variables over time was estimated using the least squares method, after which one-way analysis of variance of mean values was performed. In Dentistry, the journals of the top quartiles show a trend to publish increasing amounts of systematic reviews and meta-analysis, than the ones of the third and fourth quartile. On the other hand, globally, there was virtually no increase in narrative reviews, clinical trials and randomized controlled trial. Possible causes of this behavior are also discussed in this article.