A priori power considerations in Endodontic Research. Do we miss the timeline?

Abstract

Aim To record the prevalence of a priori power calculations in manuscripts published in three endodontic journals between 2018 and 2020 and detect further associations with a number of study characteristics including journal, publication year, study design, geographic region, number of centres and authors, whether the primary outcome pertained to a statistically significant effect and whether confidence intervals (CIs) were reported. Methodology The contents of the three leading endodontic journals with the highest impact factor (International Endodontic Journal, IEJ; Journal of Endodontics, JOE; and Australian Endodontic Journal, AEJ) were assessed from January 2018 to December 2020. The proportion of articles reporting a priori power calculations were recorded, and relevant associations as described above were assessed. Univariable and multivariable logistic regression were used to identify significant predictors, whilst interaction and linear trend effects were also considered. Results A total of 716 original research articles were included. The vast majority were published in the JOE (417/716; 58.2%), followed by the IEJ (225/716; 31.4%) and the AEJ (74/716; 10.4%). Overall, a priori power considerations were reported in 243 out of 716 articles (33.9%). The IEJ presented 1.61 times higher odds for including a priori power considerations compared to JOE (adjusted odds ratio, OR = 1.61; 95%CI: 1.11, 2.34), whilst for the AEJ, the corresponding odds were 41% lower in comparison to JOE (adjusted OR = 0.59; 95%CI: 0.31, 1.14). For each additional year indicating more recent publication, the odds for adopting appropriate reporting practices for power considerations were increased by 64% (adjusted OR = 1.64; 95%CIs: 1.32, 2.04). There was strong evidence that interventional research was associated with 10.54 times higher odds for a priori considerations compared to observational study design (adjusted OR = 10.54; 95%CIs: 5.50, 20.19). Conclusions The high prevalence of failure to include a priori power considerations was indicative of suboptimal reporting in endodontic research, in the three endodontic journals analysed. Although the condition improved over time, efforts to incorporate a correct determination of the required sample size at the design stage for any future study should be endorsed by journal editors, authors and the scientific community.

Quick retreatment with plastic core obturators in curved canals: an in vitro study.

“…In addition, several articles that evaluate retreatment time do not provide sample size calculation or statistical power [3,6,7,19,20]; between 2018 and 2020, 33.9% of articles published in 3 endodontic journals missed a priori sample size calculation and determination of study power, therefore, this is a prevalent problem in the endodontic literature [21]. It is essential to summarize the information on the different techniques for retreatment, as well as the methodologies used to see which are more relevant and can be translated to daily clinical practice [16].…”

Assessment of spin in abstracts of Endodontic Systematic Reviews with meta‐analyses published between 2010 and 2022. Are we in need of more transparent interpretation of findings?

“…Contrary to our findings, the study of Makou et al (2021) identified study design‐oriented spin , with observational type SRs being mostly affected, whilst again a trend was observed for non‐significant meta‐analyses to be less affected by this flaw (Makou et al, 2021). The former effect has been demonstrated in other types of methodological flaws of original studies as well because observational and non‐randomized studies have been considered of lower quality overall in terms of evidence perspectives (Gratsia et al, 2019; Koletsi et al, 2015; Tzanetakis & Koletsi, 2021b, 2021c). Regarding the latter, one might consider this is related to the overall nature of the identified spin domains, with authors of most SRs being more prone to overstress the conceivably significant findings, disregarding the limitations of the contributing primary studies or overstating a statistically significant p ‐value result (Koletsi et al, 2009).…”

“…In this report, international collaborations as well as trial registration accounted for improved reporting and interpretation, contrary to spin practices. The latter has also been acknowledged universally as a backbone practice for providing transparency and credibility in disseminated research findings (Fleming et al, 2015; Koufatzidou et al, 2019; Tzanetakis & Koletsi, 2021b, 2021c). Similarly, abstracts of RCTs in periodontology and implantology have been reported to present spin in almost 70% of their reports (Wu et al, 2020).…”

Critical analysis of research methods and experimental models to study removal of root filling materials

“…Unfortunately, sample size power calculations were not common in studies assessing root filling material removal. A recent study has shown this to be a prevalent issue in the endodontic literature with an a priori calculation present in only 33.9% of articles between 2018 and 2020 (Tzanetakis & Koletsi, 2021).…”