The level of evidence in prosthodontics in relation to author’s characteristics: an analysis of three leading prosthodontics journals

Purpose The purpose of this study was to examine the level of evidence (LOE) characteristics and associated factors that change over time in three leading prosthodontics journals. Materials and methods Articles published in The Journal of Prosthetic Dentistry (JPD), International Journal of Prosthodontics (IJP), and Journal of Prosthodontics (JP) in 2013 and 2020 were reviewed by eight independent reviewers. After applying exclusion and inclusion criteria, the number of authors, the corresponding author's educational degree, corresponding author's origin in each clinical research article were recorded. The included articles were rated by reviewers according to the level of evidence criteria and proposed level of evidence-associated factors. Descriptive statistics, univariable, and binary logistic regression analysis were performed to investigate dependent variables and potentially associated factors. All independent variables with a significant effect were analyzed by using a multivariable test. The entry and exit alpha level were set at αE =0.15. The statistical significance was set at α=0.05. Results A total of 439 articles from 3 selected journals for the years studied met the inclusion criteria. The percentages of level 1, 2, 3, 4, and 5 articles were 2.7%, 11.4%, 9.6%, 13.4% and 62.9%, respectively. Univariable analysis results demonstrated significant associations related to the number of authors (P=.005), the corresponding author's educational degree (P=.022), and the corresponding author's geographic origin (P=.042). Multivariable analysis results demonstrated significant associations related to the number of authors (P=.002), and the corresponding author's geographic origin (P=.014). Conclusions The number of authors, CA degree, and CA origin had a significant association with the LOE of included prosthodontic studies. Although there was an increase in the number of publications from 2013 to 2020, the level of evidence trend shows no improvement over the years.