Trial registration and selective outcome reporting in Endodontic Research: Evidence over a 5-year period

Adherence to Registration and Selective Outcome Reporting in Randomized Clinical Trials Published in Endodontic Journals Over the Past 5 Years: A Meta-Research Study

INTRODUCTION

Prospective registration of randomized clinical trials (RCTs) is highly recommended to ensure research transparency and prevent selective outcome reporting (SOR). This study aimed to evaluate the adherence to registration and the presence of SOR in RCTs published in endodontic journals over the past 5 years.

METHODS

Electronic searches were conducted in PubMed and the libraries of the Journal of Endodontics, International Endodontic Journal, European Endodontic Journal, and Australian Endodontic Journal. Two reviewers were involved in the study selection and evaluation. Publications were assessed for key methodological aspects, including the presence and timing of trial registration. RCT registries were examined to identify discrepancies between publication and registered protocols and the presence of SOR. Logistic regression was used to explore the effect of study variables on registration practices and SOR.

RESULTS

Of the 144 RCTs included, 104 (72.2%) were registered. Among those registered, only 19 (18.3%) adhered to prospective registration. Registration practice increased by 53% per year (OR 1.53; 95% CI: 1.34-2.08; P < .01). Discrepancies between publication and protocol were identified in 55.8% of studies, primarily related to sample size (33.7%). SOR was identified in 41 trials (39.4%), mainly due to discrepancies in the outcome time frame (18.3%). Studies evaluating multiple outcomes had 4.95 times higher odds of exhibiting SOR (OR 4.95; 95% CI: 1.63-12.95; P < .01). Furthermore, studies that were registered retrospectively or exhibited discrepancies between publication and protocol accounted for 6.10 times (OR 6.10; 95% CI: 1.81-18.96; P = .03) and 5.61 times (OR 5.61; 95% CI: 2.93-16.58; P < .01) higher odds of exhibiting SOR, respectively.

CONCLUSIONS

RCTs published in endodontic journals over the past 5 years presented low adherence to prospective trial registration and a high prevalence of SOR.

Reporting quality of scoping reviews in endodontics: A meta-research study

OBJECTIVES

To evaluate the reporting quality of Scoping Reviews (ScRs) in endodontics according to the PRISMA Extension Checklist for Scoping Reviews (PRISMA-ScR) and to analyse their association with a range of publication and methodological/reporting characteristics.

METHODS

Pubmed, Scopus, and Web of Science databases were searched up to 31 January 2024 to identify scoping reviews in the field of endodontics. An additional search was performed in three leading endodontic journals. Study selection and appraising the quality of the studies was carried out independently by two reviewers. Each of the 20 PRISMA-ScR items were allocated a score of either 0, 0.5 or 1 to reflect the completeness of the reporting. An item-specific and overall percentage reporting quality score was calculated and reported through descriptive statistics across a range of publication, as well as methodological/reporting characteristics. A univariable and multivariable quantile regression was performed to identify the effect of publication and methodological/reporting characteristics (year of publication, journal, inclusion of an appropriate reporting guideline, and study registration) on the overall percentage reporting quality score. Association of reporting quality score with publication characteristics was then investigated.

RESULTS

A total of 40 ScRs were identified and included for appraisal. Most of the studies were published from 2021 onwards. The overall median reporting quality score was 86%. The most frequent items not included in the studies were: a priori protocol registration (22/40 compliant; 55%), and reporting of funding (16/40 compliant; 40%). Other key elements that were inadequately reported were the abstract (7/40 compliant; 18%), the rationale and justification of the ScR (21/40 compliant; 52%) and the objectives of the study (18/40 compliant; 45%). Studies that adhered to appropriate reporting guidelines were associated with greater reporting quality scores (β-coefficient: 10; 95%CI: 1.1, 18.9; p = .03). ScRs with protocols registered a priori had significantly greater reporting quality scores (β-coefficient: 12.5; 95%CI: 6.1, 18.9; p < .001), compared with non-registered reviews.

CONCLUSIONS

The reporting quality of the ScRs in endodontics varied and was greater when the ScR protocols were registered a priori and when the authors adhered to reporting guidelines.

Selective outcome reporting among randomized controlled trials published in leading dental journals: A research-on-research study

OBJECTIVES

To study the prevalence and manifestation of selective outcome reporting (SOR) among randomized controlled trials (RCTs) published in leading dental journals, and to explore the association between SOR and potentially related factors.

METHODS

We hand-searched RCTs published in the leading dental journals between 2018 and 2023. RCTs with registrations and defined primary outcomes were included, and their relevant characteristics were extracted for analysis. Discrepancies between publication and corresponding registration were compared regarding primary outcome and other study characteristics. The generalized estimating equation model was applied to identify factors associated with SOR.

RESULTS

Two hundred and seventy trials were included. SOR was identified in 51.5% (n = 139) of the included RCTs with the discrepancy in the assessment timing of the primary outcome as the most common manifestation (n = 86, 31.9%). Substantial discrepancies were observed regarding sample size (n = 148, 54.8%) and source of funding (n = 105, 38.9%). Sample size [odds ratio (OR) 0.61, 95% confidence interval (CI) 0.40 to 0.92], timing of registration (OR 2.10, 95% CI 1.03 to 4.31), and discrepancy in follow-up length (OR 32.01, 95% CI 11.80 to 86.83) were identified as statistically significant factors associated with SOR.

CONCLUSIONS

SOR was prevalent among RCTs in leading dental journals. Researchers and other stakeholders should be aware of this reporting issue and make joint efforts to improve the outcome reporting quality.

CLINICAL SIGNIFICANCE

The findings of this research-on-research study indicate a substantial presence of SOR in the field of dentistry. Such bias can potentially mislead readers and distort the pooled effect estimates in evidence synthesis, ultimately influencing clinical decision-making.

Data sharing and transparency indicators in published RCTs in Oral Health between 2017 and 2023

OBJECTIVES

To record the proportion of data sharing reporting in terms of primary data and/or statistical code of Randomized Controlled Trials (RCTs), published across 12 high impact journals in Dentistry, covering 6 specialty domains. Associations with certain journal, publication and outcome characteristics were examined. Transparency indicators such as registration or funding statements were assessed.

METHODS

We identified and included all RCTs published from January 1st, 2017 to December 31st, 2023 in journals of high impact of the following domains: Periodontology, Endodontics, Restorative Dentistry/Prosthodontics, Orthodontics, Pediatric Dentistry, Oral/Maxillofacial Surgery. The primary outcome was the proportion of RCTs reporting their intent to share or openly shared primary data and we tested for associations with potential predictors. Funding, registration, and statistical code/script sharing practices were also examined.

RESULTS

A total of 752 RCTs were included, of which only 119 (15.8%) either openly provided their data or included a statement of intention to share upon request. Only one study openly provided the statistical code underlying the analysis used. RCTs in periodontology more frequently included statements about positive intent to share (57/210;27.1%), followed by Orthodontics (35/157;22.3%). Significant effects of year, dentistry domain and continent of authorship on data sharing practices were identified (p < 0.001 in all cases). There was evidence that registered RCTs had 2.04 times higher odds for intention to share data (95%confidence interval: 1.06, 3.92;p = 0.03).

CONCLUSIONS

Overall, in oral health RCTs, empirical evidence suggested very low prevalence of positive data sharing practices. Enhancing transparency is pivotal in promoting reproducibility and credibility of research findings.

CLINICAL SIGNIFICANCE

The findings of this empirical report bring attention to key transparency indicators in randomized controlled trials. These largely impact on the credibility and reproducibility of the evidence base for clinical decision making.

Reporting completeness of scoping reviews in orthodontic literature up to 2022. An empirical study

AIM

To assess the quality of reporting of Scoping Reviews (ScRs) in Orthodontics according to the PRISMA Extension Checklist for Scoping Reviews (PRISMA-ScR). Our secondary aim was to identify publication characteristics, such as year of publication, journal, inclusion of a reporting guideline, and study registration, associated with ScRs reporting quality.

MATERIALS AND METHODS

Pubmed, Scopus, and Web of Science Core Collection were searched as of 1 August 2022 for identification of orthodontic ScRs. This was supplemented by electronic searches within the contents of eleven specialty journals. The item-specific and overall reporting quality score of the examined orthodontic ScRs, based on the PRISMA Extension Checklist for Scoping Reviews were recorded. Association of reporting quality score with publication characteristics was further examined.

RESULTS

A total of 40 ScRs were identified and included, with a mean reporting quality score of 73.0 per cent (standard deviation = 14). The majority of studies were published from 2020 onwards (32/40; 80.0%). Of the most adequately reported items were the summary of the evidence description in the Discussion (38/40; 95.0%) and the selection of the sources of evidence in the Results section (34/40; 85.0%). Protocol registration and reporting of limitations were missed in almost half of the ScRs (19/40; 47.5%), while less than half studies were adequately justified (18/40; 45.0%). According to the multivariable linear regression, adherence to appropriate reporting guidelines resulted in improved reporting quality score by 10 per cent (β-coefficient: 0.10; 95% CI: 0.002, 0.19; P = 0.04), conditional on year and journal of publication. Year, journal of publication, and registration practices did not appear as significant predictors (P > 0.05 in all instances).

CONCLUSIONS

The reporting quality of the examined orthodontic ScRs was suboptimal, with questionable justification for their conduct and certain items being mostly affected.

Not enough SPIRIT shown in the registration and reporting of orthodontic trial protocols

BACKGROUND

To reduce bias associated with selective reporting, the registration and publication of clinical trial protocols before or at the time of patient enrolment has been advocated. The aim of this investigation was to assess the frequency of registration and reporting adherence of orthodontic trial protocols pre- and post-introduction of the Standard Protocol Items Recommendations for Interventional Trials (SPIRIT) Statement.

MATERIALS AND METHOD

Trial protocols registered in four online registries were sourced at two time periods: (1 January 2010-1 January 2013) and (1 January 2017-1 January 2021). Protocols were screened and data extracted, in duplicate and independently. The reporting adherence of each protocol was assessed in relation to the thirty-three item SPIRIT statement. Fisher's exact test was used to determine associations between time periods and trial protocol characteristics. Median regression was implemented to assess potential associations between the percent score per protocol and protocol characteristics.

RESULTS

A total of 100 protocols were analysed. Thirty-three and sixty-seven protocols were registered in the first and second time periods, respectively. An association between period and the timing of registration (prospectively or retrospectively) (P < 0.001) and funding source (University or Company) (P < 0.001) was evident. Overall, 25 of the 33 (75.5%) SPIRIT statement items were not reported in either timeframe. The median percent reporting quality score was 26.9 (IQR 6.9). The type of registry was associated with percent scores and published studies received better percent scores compared to unpublished studies and academic or private protocol submissions.

CONCLUSIONS

There is a general lack of awareness of the importance and relevance of the SPIRIT statement. Registration of orthodontic trial protocols has apparently improved; however, 75.5% SPIRIT statement items were not reported in either study time period. The registration and reporting of orthodontic trial protocols should be advocated to circumvent issues relating to selective reporting and outcome reporting bias.

Scoping reviews in orthodontics: are they justified?

BACKGROUND

Scoping Reviews (ScRs) have emerged in the orthodontic literature as a new methodological perspective to collate and summarize scientific evidence. The aim of the present study was to identify and record the proportion of Scoping Reviews in orthodontics that have been clearly and adequately justified, based on the methodological framework of such types of reviews. Associations with a number of publication characteristics were also sought. Three major databases, namely PubMed, Scopus and Web of Science Core Collection, as well as 11 specialty orthodontic journals were electronically sought from inception until August 1, 2022, for ScRs. The primary outcome pertained to whether the published reports of the ScRs included an appropriate justification and explanation for the selection of this kind of knowledge synthesis methodology. Potential association with year, journal, continent of authorship, number of authors, methodologist involvement, appropriate reporting guidelines and registration practices followed were explored.

RESULTS

A total of 40 ScRs were eligible for inclusion, with the majority not being adequately justified (22/40; 55.0%). The majority of studies were published from 2020 onward (32/40; 80.0%). The regression model did not reveal any significant association between justification of ScRs and a number of publication characteristics (p > 0.05 at all levels).

CONCLUSIONS

Less than half of the included ScRs were adequately justified in terms of selection of the appropriate synthesis methodology. Awareness should be raised in the scientific community regarding the correctness of the use of this newly emerging type of study in orthodontics, to safeguard against any trace of research waste.

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?

AIM

Spin refers to reporting, interpretation and extrapolation related distortion or manipulation of the findings of a study. The aim of this report was to identify the prevalence and extent of spin in the abstracts of systematic reviews (SRs) including meta-analyses in the scientific field of Endodontics.

METHODOLOGY

A sensitive and inclusive search strategy in PubMed was developed to identify eligible SRs with meta-analyses in Endodontics, supplemented by an electronic search within 3 major specialty journals, from January 1, 2010 to April 16, 2022. Inclusion and extent of spin was recorded, per domain and following issues related to misleading reporting, interpretation and inappropriate extrapolation of meta-analyses' findings. Association of spin with publication characteristics such as year, journal type, number of authors, continent of authorship, funding, primary study design and significance of the outcome was explored.

RESULTS

A hundred and eighty-six SRs with meta-analyses were retrieved, and inclusion of spin was detected in 125 abstracts (67.2%), for one or more domains. The majority of abstracts were affected by more than one types of spin (91/125; 72.8%). There was evidence that abstracts of meta-analyses of non-significant findings had 60% lower odds for inclusion of spin (Odds ratio, OR: 0.40; 95%CI: 0.19, 0.83; p= 0.04), after adjusting for year, journal type and number of authors.

CONCLUSIONS

Misleading reporting and misinterpretation of findings in abstracts of meta-analyses is evident in endodontic research. Efforts should be reinforced to increase awareness within the scientific and academic community to improve adherence to transparent reporting and interpretation.

Publication bias in randomized controlled trials in dentistry. What factors affect statistical significance of outcomes?

OBJECTIVES

To record the proportion of Randomized Controlled Trials (RCTs) reporting significant (versus non- significant) primary outcomes, published across 12 high impact journals in Dentistry, covering 6 specialty domains. Associations with certain journal, publication and outcome characteristics were examined.

METHODS

We identified and included all RCTs published from January 1st, 2017 to December 31st, 2021 in the two journals with the highest impact factors (Clarivate Analytics, 2020) from each of the following domains: Periodontology, Endodontics, Restorative Dentistry/ Prosthodontics, Orthodontics, Paediatric Dentistry, Oral and Maxillofacial Surgery. The primary outcome was the proportion of significant/ non- significant findings reported for the primary outcomes under study, while a range of characteristics such as: journal, year of publication, impact factor, funding, registration and others, were tested for associations.

RESULTS

A total of 474 RCTs were identified and included, with the majority reporting statistically significant outcomes (321/474; 67.7%). The multivariable model revealed significant effects of predictors related to specialty domain (p = 0.01), continent (p = 0.003) and registration (p = 0.004). Compared to Periodontology, RCTs published in Endodontics (OR= 0.40; 95%CIs: 0.22, 0.76) and Orthodontics (OR= 0.41; 95%CIs: 0.23, 0.74) were less likely to present statistically significant effects. There was strong evidence that registered trials presented lower odds of reporting statistically significant findings (OR= 0.52; 95%CIs: 0.34, 0.81).

CONCLUSIONS

The entirety of dentistry domains demonstrated preferential publication practices of outcomes considered as "successful" and statistically significant, with domains such as Orthodontics and Endodontics being more balanced. Trial non- registration is still prevalent and associated with reporting of statistically significant effects.

CLINICAL SIGNIFICANCE

The findings of this empirical report bring attention to the interpretation of Systematic Reviews (SRs) conclusions. These largely depend on the availability and nature of outcomes of randomized controlled trials (RCTs) on a topic, which may impact on the synthesized estimate of a pooled effect and its direction.