Selective outcome reporting in randomized clinical trials of dental implants

Selective outcome reporting in randomized clinical trials using the third molar surgery model

Selective outcome reporting (SOR) can threaten the validity of results found in clinical trials. Some studies in the literature have analyzed SOR in dentistry, but there is no study that has observed SOR in clinical trials in oral and maxillofacial surgery. Impacted third molar surgery is one of the most used models in clinical trials to study mainly analgesic and anti-inflammatory drug interventions. Our study aimed to evaluate the prevalence of SOR in publications employing the third molar extraction clinical trial model, and to verify whether there was an association between the statistical significance of outcomes and other characteristics that could lead to SOR. A systematic search was performed on the ClinicialTrials.gov platform for randomized clinical trial protocols, using the condition of third molar extraction. The corresponding published articles were sourced in PubMed, Scopus, and Embase databases, and compared with the registered protocols regarding the methodological data, in terms of: sample calculation, primary outcome identification, end-point periods, insertion of new outcomes in the publication, and results of outcomes. 358 protocol records were retrieved; 87 presented their corresponding articles. SOR was identified in 28.74% of the publications, and had a significant relationship with changes in the protocol, insertions of new outcomes, and discrepancies in the types of study. General risk of bias was found to be low. There were associations between SOR and the discrepancies in terms of the type of study, the choice of new outcome, and changes in the history of protocol records. The prevalence of SOR in clinical research using the third molar extraction surgery model is moderate. The quality of the scientific reporting of the results and, consequently, the certainty of evidence relating to the intervention tested can be overstated, increasing the chances of misinterpretation by health professionals.

Factors influencing the impact of randomized clinical trials on dental implants: A bibliometric analysis

OBJECTIVE

To analyze bibliometrics, characteristics, and the risk of bias of randomized controlled trials (RCTs) on dental implants published in six high-impact factor journals and to identify factors contributing to citation number.

MATERIALS AND METHODS

A systematic electronic search was conducted in four databases (PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials) to identify RCTs on dental implants published in six dental journals between 2016 and 2017. Twenty-five bibliometric variables and paper characteristics were extracted to evaluate their contribution to the citation count. Risk of bias analysis was performed using the RoB2 tool. Negative binomial regression was used to examine the effects of predictor variables on the Citation count. Significance level was set to 5%.

RESULTS

A total of 150 RCTs included received a cumulative citation count of 3452 until July 2022. In the negative binomial regression analysis, open-access RCTs exhibited 60% more citations, and RCTs that presented statistical significance received 46% more citations. Conversely, first author affiliations from Africa, Asia and Oceania continents showed 49% fewer citations than publications from Europe. Regarding the risk of bias, 73.3% of the RCTs had some concerns, while 26% were deemed to have a high risk of bias. Only one RCT (0.07%) showed a low risk of bias.

CONCLUSION

Within the limitation of the study, factors such as open access, statistically significant results, and country influence the number of citations received by the RCTs on dental implants.

Should informed consent and information related to patient recruitment in clinical trials be available to the reader of scientific articles? A case study in dentistry

Ethical aspects in research should be transparently reported. This study aimed to investigate whether informed consent and information related to patient recruitment in clinical studies are well reported in the scientific literature. Randomized clinical trials (RCTs) on root coverage procedures published between November 2016 and November 2021 were selected from the PubMed database. Items/questions were used to guide the extraction of data related to patient recruitment, with a focus on the detailed report of informed consent used to clarify the research to the patient. Data were extracted from the published article and the respective research protocol published in a public registry. Information related to potential selective outcome reporting (SOR) was also extracted. In total, 187 documents were initially screened and 74 reports of RCTs were included. No informed consent was published in the article. Only one research protocol provided a link to the informed consent. Deviations from reporting in the research protocol and published article were found, suggesting SOR. Informed consent and information related to patient recruitment in RCTs on root covering procedures are severely underreported. The present findings may stimulate further discussion and debate on the need for making this information publicly available.

Estimating the prevalence of discrepancies between study registrations and publications: a systematic review and meta-analyses

OBJECTIVES

Prospectively registering study plans in a permanent time-stamped and publicly accessible document is becoming more common across disciplines and aims to reduce risk of bias and make risk of bias transparent. Selective reporting persists, however, when researchers deviate from their registered plans without disclosure. This systematic review aimed to estimate the prevalence of undisclosed discrepancies between prospectively registered study plans and their associated publication. We further aimed to identify the research disciplines where these discrepancies have been observed, whether interventions to reduce discrepancies have been conducted, and gaps in the literature.

DESIGN

Systematic review and meta-analyses.

DATA SOURCES

Scopus and Web of Knowledge, published up to 15 December 2019.

ELIGIBILITY CRITERIA

Articles that included quantitative data about discrepancies between registrations or study protocols and their associated publications.

DATA EXTRACTION AND SYNTHESIS

Each included article was independently coded by two reviewers using a coding form designed for this review (osf.io/728ys). We used random-effects meta-analyses to synthesise the results.

RESULTS

We reviewed k=89 articles, which included k=70 that reported on primary outcome discrepancies from n=6314 studies and, k=22 that reported on secondary outcome discrepancies from n=1436 studies. Meta-analyses indicated that between 29% and 37% (95% CI) of studies contained at least one primary outcome discrepancy and between 50% and 75% (95% CI) contained at least one secondary outcome discrepancy. Almost all articles assessed clinical literature, and there was considerable heterogeneity. We identified only one article that attempted to correct discrepancies.

CONCLUSIONS

Many articles did not include information on whether discrepancies were disclosed, which version of a registration they compared publications to and whether the registration was prospective. Thus, our estimates represent discrepancies broadly, rather than our target of undisclosed discrepancies between prospectively registered study plans and their associated publications. Discrepancies are common and reduce the trustworthiness of medical research. Interventions to reduce discrepancies could prove valuable.

REGISTRATION

osf.io/ktmdg. Protocol amendments are listed in online supplemental material A.

Selective outcome reporting bias is highly prevalent in randomized clinical trials of nonsurgical periodontal therapy

Selective outcome reporting (SOR) is a type of bias that can compromise the validity of results and affect evidence-based practice. SOR can overestimate the effect of an intervention and lead to conclusions that a treatment is effective when it is not. This study aimed to investigate the prevalence of SOR in publications of RCTs on nonsurgical periodontal therapy (NSPT) and to verify associated factors. The protocols were searched and selected on the www.clinicaltrials.gov platform up to January 16, 2022. Corresponding publications were identified, and data extraction and discrepancy analysis were performed. The risk of bias was assessed according to the RoB2 tool. One hundred forty-five studies (174 publications) were included. The prevalence of SOR was 49.7% and was unclear in nearly one third of studies (27.6%). Only 31.7% of the primary outcomes were completely described in the publications. The overall risk of bias was high in 60% of the included studies. SOR was associated with statistical significance (p < .001), and multiple publications of the same study (p = .005). Our study demonstrated the high prevalence of SOR, highlighting the need to improve the quality of reporting of RCTs on NSPT studies.

Selective outcome reporting in paediatric dentistry restorative treatment randomised clinical trials-A meta-research

BACKGROUND

Selective outcome reporting (SOR) is a bias that occurs when the primary outcome of a randomised clinical trial (RCT) is omitted or changed.

AIM

To evaluate the prevalence of SOR in RCTs on restorative treatment in primary teeth.

DESIGN

We conducted an electronic search on ClinicalTrials.gov and the World Health Organization platform (International Clinical Trials Registry Platform) on 1^st of April 2021, with no registry time or language restrictions. We included RCT protocols that evaluated restorative treatments in primary teeth and excluded trials that did not have a complete publication in a scientific journal. The chi-squared test was used to identify the association between SOR and variables as a discrepancy in the follow-up period, the timing of registration, the type of sponsorship and the type of study design (α = 5%).

RESULTS

Of the 294 identified protocols, 30 were included in the study. 83.3% of trials were registered retrospectively. SOR was observed in 53.3% (n = 16) of the published trials and was significantly associated with a discrepancy in the follow-up period (p = .017).

CONCLUSIONS

The high prevalence of SOR in RCTs on restorative treatment proves that this is a prominent threat. A proper preregistered protocol, declaration of any protocol deviation and allowance of stakeholders to compare the protocol with that of the submitted papers will achieve transparency.

Bone preservation or augmentation simultaneous with or prior to dental implant placement: A systematic review of outcomes and outcome measures used in clinical trials in the last 10 years

AIM

To evaluate outcome measures and methods of assessment in clinical studies on bone augmentation/preservation procedures for the placement of dental implants.

MATERIALS AND METHODS

A systematic search was performed on three databases from January 2011 to April 2021 to identify clinical studies reporting on any type of bone augmentation/preservation procedure. The outcomes that have been used to assess efficacy or performance in each study were registered and assigned to different domains (group of outcomes). The review followed the Preferred Reporting Items for Systematic Review and Meta-Analyses statement.

RESULTS

Seven-hundred and eighty-three publications were included. Only 81.8% of the papers had a clear definition of their primary outcome. The rate of complications (59.3%), implant survival (58.2%), 3D radiographic bone gain/change (30%), marginal bone level (MBL; 29%), and histological outcomes (25.5%) were the most frequently reported outcome domains. The most commonly used primary outcome was 3D radiographic bone gain/change (25.8%), followed by implant survival (13.0%). Patient-reported outcome measures (PROMs) were reported in 15.7% of studies. Differences in the reported outcomes were observed among different types of bone preservation/augmentation interventions (i.e., alveolar ridge preservation, immediate implants, horizontal and/or vertical ridge augmentation, and sinus floor augmentation).

CONCLUSION

Within the past decade, great heterogeneity was observed among the outcomes considered in studies evaluating bone preservation/augmentation procedures. Three-dimensional radiographic bone gain/change was the most routinely reported main outcome variable, while PROMs were rarely reported.

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

AIM

To assess the prevalence of registration of clinical trials in endodontic research and to identify outcome reporting discrepancies between trial registration entries and respective final publications. Associations with publication characteristics, such as journal, year of publication, origin, number of centres and authors, funding and statistical significance of the findings, were also sought.

METHODOLOGY

All reports of endodontic randomized controlled trials (RCTs) published in 4 endodontic specialty and 4 general dental journals from 1 January 2016 to 31 December 2020 were identified. Trial registration frequency patterns were assessed for the included RCTs, whilst for the ones registered, outcome reporting discrepancies were recorded. Article characteristics such as year of publication, geographic region, number of centres, authors participating in the publication, funding, type of registration and others were identified. Descriptive statistics and univariable/multivariable logistic regression were performed to examine the effect of study characteristics on identified registration practices.

RESULTS

One hundred and fifty-five RCTs were included, with the majority published in specialty journals (121/155; 78.1%). A total of 42.6% of the identified RCTs was registered (66/155), mostly retrospectively (38/66; 57.6%). There was strong evidence that each additional year for more recent publication accounted for 1.42 times higher odds of being registered (adjusted Odds Ratio = 1.42; 95%CI: 1.11, 1.80; p = .004). More than 1/3 of registered RCTs presented outcome reporting discrepancies (24/66; 36.4%), whilst such inconsistencies were almost evenly distributed between primary and secondary outcomes.

CONCLUSIONS

Trial registration policies in endodontic research should be reviewed and active endorsement of prospective registration practices should be prioritized for better clarity and transparency of the disseminated research. Outcome reporting discrepancies shall thus be eliminated, offering increased credibility in research findings and eliminating bias in this respect.

Selective outcome reporting in root coverage randomized clinical trials

BACKGROUND

Outcome discrepancies between protocols and respective publications represent a concerning bias. The purpose of this study was to assess the prevalence of selective outcome reporting (SOR) in root coverage randomized clinical trials (RCTs).

METHODS

Published root coverage RCTs (July 2005 to March 2020) were included if a corresponding protocol could be identified in a public registry. Discrepancies between protocol and its correspondent publication(s) were compared regarding primary and secondary outcomes and other study characteristics. Associations between trial characteristics and SOR were evaluated.

RESULTS

Forty four studies (54 publications) were included. The majority of studies (77.3%) were retrospectively registered. SOR was frequent (40.9% of trials) and consisted of primary outcome downgrade (22.7%); secondary outcome upgrade (11.4%); new primary outcome introduced in publication (25%); protocol primary outcome omitted from publication (13.6%) and discrepancy in primary outcome timing (18.2%). SOR was unclear in 20.5% of studies and favoured statistical significance in 12 studies (27.3%). SOR was significantly associated with study significance (p < 0.001) and unclear outcome definition in the publication (p < 0.001). Only a third (32.8%) of primary outcomes were completely defined.

CONCLUSIONS

The present study identified high prevalence of SOR in root coverage RCTs.

How researchers should select the best outcomes for randomised clinical trials in paediatric dentistry?

Randomised clinical trial (RCT) is the best study design to evaluate the effect of the treatment and preventive healthcare procedures. The effects of the tested treatments on patient's health are compared in terms of outcomes, which are used to evaluate the participants' health changes. However, these outcomes should be relevant for the target population. In that way, RCTs represent the type of primary study design that provides the most reliable evidence to implement therapies into the clinical practice. In this review, an outline of some aspects related to the choice of RCTs' outcomes was presented, focusing on the conduction of relevant trials in Paediatric Dentistry. The importance and necessity of defining a primary outcome were addressed, preferentially a clinically relevant endpoint. The patients should perceive this outcome, and changes in this variable should reflect directly patient's health improvement or impairment. Moreover, considerations about the objective or subjective variables, use of surrogate outcomes, and the increasing tendency to develop core outcome sets were also presented in this review. The main idea of this manuscript is the RCTs must evaluate outcomes relevant to the children's oral health in order to contribute to the implementation of treatments in the evidence-based health practice.

Spin in the abstracts of randomized controlled trials in periodontology and oral implantology: A cross-sectional analysis

OBJECTIVES

To investigate the presence and characteristics of spin (a distorted interpretation to make research findings seem favorable) in abstracts of randomized controlled trials (RCTs) in periodontology and oral implantology, and to explore its associated factors and influence on the subsequent literature.

MATERIALS AND METHODS

PubMed was searched to identify recent RCTs in periodontology and oral implantology, whose primary outcome was non-significant. Spin in abstracts was assessed and categorized according to pre-determined spin strategies. The associations between study characteristics and the presence / severity of spin were analyzed using multivariable logistic regressions.

RESULTS

196 abstracts were included, 137 (69.9%) of which had spin. 57 (29.1%) abstracts had spin in the Results Section, 126 (64.3%) had spin in the Conclusion Section. The main spin strategies in the Results and Conclusion Sections were focusing on secondary outcomes (16.3%) and focusing on within-group comparisons (28.6%), respectively. The presence of spin was associated with number of centers (OR=0.28, 95% CI: 0.11-0.73; p=0.009) while its severity was associated with topic (OR=0.24, 95% CI: 0.08-0.70; p=0.009).

CONCLUSIONS

The frequency of spin is relatively high among published RCT abstracts in periodontology and oral implantology. Findings reported in these abstracts need to be interpreted with caution.

The level of evidence, scientific impact and social impact of clinical studies in periodontology: A methodological study

AIMS

To analyse the level of evidence (LOE) of clinical studies in the field of periodontology, and to investigate whether LOE is a predictor of scientific impact and social impact.

MATERIALS AND METHODS

Clinical studies published in five leading periodontal journals during 2015-2019 were identified. The LOE of included studies were assessed with a modified LOE classification system based on Oxford 2009 LOE, Oxford 2011 LOE and GRADE guidelines. Citation counts were harvested from Web of Science and Scopus. Altmetric Attention Scores (AAS) were obtained from Altmetric Explorer. Multivariable generalized estimation equation (GEE) analyses were used to investigate association between LOE and citation count, as well as between LOE and AAS.

RESULTS

Among 768 studies included, the proportion of level-1, level-2, level-3 and level-4 was 10.4%, 44.8%, 13.7% and 31.1%, respectively. In the multivariable GEE analyses, high LOE was a significant predictor of higher average citation count (p = .010) and higher AAS (p < .001).

CONCLUSION

The LOE of clinical studies in the periodontal field is relatively high in general, although it varies significantly in different journals. Studies with high LOE tend to have greater scientific impact and social impact than low LOE studies.