Positive association between conflicts of interest and reporting of positive results in randomized clinical trials in dentistry

Differences in the reporting of conflicts of interest and sponsorships in systematic reviews with meta-analyses in dentistry: an examination of factors associated with their reporting

BACKGROUND

Reporting conflicts of interest (COI) and sources of sponsorship are of paramount importance in adequately interpreting the results of systematic reviews. Some evidence suggests that there is an influence of COI and sponsorship on the study results. The objectives of this meta-research study were twofold: (a) to assess the reporting of COI and sponsorship statements in systematic reviews published in dentistry in three sources (abstract, journal's website and article's full text) and (b) to assess the associations between the characteristics of the systematic reviews and reporting of COI.

METHODS

We searched the PubMed database for dental systematic reviews published from database inception to June 2023. We assessed how COI and sponsorship statements were reported in the three sources. We performed a logistic regression analysis to assess the associations between the characteristics of the systematic reviews and the reporting of COI.

RESULTS

We assessed 924 abstracts published in PubMed and on the corresponding journals´ websites. Similarly, full texts associated with the 924 abstracts were also assessed. A total of 639 (69%) and 795 (88%) studies had no statement of COI in the abstracts on PubMed and the journal's website, respectively. In contrast, a COI statement was reported in 801 (87%) full texts. Sponsorship statements were not reported in 911 (99%) and 847 (93%) abstracts published in PubMed and a journal´s website, respectively. Nearly two-thirds of the full-text articles (N = 607) included sponsorship statements. Journal access was significantly associated with COI statement reporting in all three sources. Open-access journals have significantly higher odds to report COI in PubMed and full-texts, while have significantly lower odds to report COI in the websites, compared with subscription or hybrid journals. Abstract type was significantly associated with COI statement reporting on the journal's website and in the full text. Review registration based on the full text and the number of authors were significantly associated with COI statement reporting in PubMed and in the full texts. Several other variables were found to be significantly associated with COI statement reporting in one of the three sources.

CONCLUSIONS

COI and sponsorship statements seem to be underreported in the abstracts and homepage of the journals, compared to the full-texts. These results were particularly more pronounced in abstracts published in both the PubMed database and the journals' websites. Several characteristics of systematic reviews were associated with COI statement reporting.

Assessing transparency practices in dental randomized controlled trials

BACKGROUND

To evaluate transparency practices in randomized controlled trials (RCTs) in dentistry.

METHODS

This meta-research study included RCTs in dentistry regardless of topic, methods, or level of detail reported. Only studies in English were considered. We searched PubMed for RCTs in dentistry published in English from December 31, 2016, to December 31, 2021. The screening was performed in duplicate, and data extracted included journal and author details, dental specialty, protocol registration, data and code sharing, conflict of interest declaration, and funding information. A descriptive analysis of the data was performed. We generated maps illustrating the reporting of transparency items by country of the corresponding author and a heat table reflecting reporting levels by dental specialty.

RESULTS

A total of 844 RCTs were included. Only 12.86% of studies reported any information about data and code sharing. Protocol registration was reported for 50.36% of RCTs. Conflict of interest (83.41%) and funding (71.68%) declarations were present in most studies. Conflicts of interest and funding were consistently reported regardless of country or specialty, while data and code sharing had a low level of reporting across specialties, as well as low dissemination across the world. Protocol registration exhibited considerable variability.

CONCLUSIONS

Considering the importance of RCTs for evidence-based dentistry, it is crucial that everyone who participates in the scientific production and dissemination process actively and consistently promotes adherence to transparent scientific standards, particularly registration of protocols, and sharing of data and code.

Why is there a lack of evidence regarding errors and complications in periodontal and implant therapy?

The occurrence of errors, complications, and adverse effects may occur as a consequence of single or multiple events related to the clinician and/or patient. Apparently, the amount of dental literature on these undesirable outcomes has not been as prolific as that obtained for conventional primary periodontal outcome measures. This review explores the potential reasons for the lack of studies reporting on errors and complications in periodontal and implant therapy, as well as other noteworthy methodological aspects, to enlighten their impact on the selection of the best (or most appropriate) "gold standard" periodontal/implant-related treatment options, and on the overall decision-making process. The following points were addressed: (a) the importance of reporting errors and complications in clinical research; (b) the adequate reporting of errors and complications in periodontology and dental implantology; and (c) efficacy trials vs effectiveness studies and their impact on the assessment and report of periodontal and implant treatment-related risks and complications.

Low Level Laser Therapy With an 810-nm Diode Laser Affects the Proliferation and Differentiation of Premature Osteoblasts and Human Gingival Fibroblasts In Vitro

Introduction: Photomodulation is a promising strategy for optimizing tissue healing, but its photomodulatory effects on the synergistic cellular metabolism of gingival and bony tissues remain largely unknown. The aim of the present study was to evaluate the photomodulatory effects of a diode laser (810 nm) on osteoblasts, HGFs and their co-cultures in vitro. Methods: Primary cultures of HGFs, cultures of immature osteoblastic cells (MG63) and their co-cultures were irradiated with a diode laser (810 nm), 15 J/cm². Cell cultures were examined for cellular proliferation (MTT assay), viability (FDA/PI staining) after 24, 48 and 72 hours and cell differentiation (qPCR of collagen type 1a - COL1a and alkaline phosphatase expressions - ALP) after 7 days. Results: Photomodulation with an 810-nm diode laser increased cell proliferation at all time points. COL1a gene expression increased both in HGF and co-cultures. ALP expression was up-regulated in osteoblastic cultures, but co-cultures with fibroblasts negated this response. Conclusion: The 810-nm diode laser positively affected cell proliferation and viability in all experimental groups. The statistically significant increased COL1a gene expression at 7 days after irradiation both in the irradiated HGF and co-cultures suggests that low-level laser therapy (LLLT) stimulated extracellular matrix (ECM) formation signaling in both cell types.

Dental Research Waste in Design, Analysis, and Reporting: A Scoping Review

Research waste is highly prevalent across biomedical investigations. We aimed to assess the evidence on the extent of research waste in dental research. We performed a scoping review of empirical evaluations of dental studies assessing the prevalence and impact of limitations in design, conduct, analysis, and reporting of research. PubMed was searched using specific terms to retrieve studies dealing with design, conduct, analysis, and reporting of studies in dentistry, with no year or language restrictions. Of the 1,807 publications identified from the search and from manual searches, 71 were included in this review. The topic and article selection was based on the expert opinion of the authors. The existing evidence suggests that, although there are improvements over time, substantial deficiencies in all areas (design, conduct, analysis, reporting) were prevalent in dental research publications. Waste in research is a multifaceted problem without a simple solution. However, an appreciation of optimal research design and execution is a prerequisite and should be underpinned by policies that include appropriate training in research methods and properly aligned incentives.

Reporting of conflict of interest and sponsorship in dental journals

OBJECTIVE

Detailed information on potential conflict of interest (COI) and sponsorship is pivotal for the adequate understanding and appropriate interpretation of the reported study results. The reporting of COI and sponsorship and any potential associations with study characteristics in publications of all dental journals with impact factor was examined.

METHODS

The Web of Science database was searched, in March 2019, for articles published from February 28, 2018 to March 1, 2019. A random a sample of 1000 articles in English was selected. Two independent authors extracted the following article characteristics: type of article, dental field, number of authors, country/continent affiliation of the first author, dental journal, journal impact factor, number of citations, Altmetric score, type of COI and sponsorship. Disagreements during data extraction were resolved by discussion and consensus. Descriptive statistics were calculated for the selected variables and multinomial logistic regression was implemented to assess the association between COI, sponsorship, and the other variables.

RESULTS

3% of dental publications declared a COI, whereas in 32.5% of publications the presence of COI was unclear. The most prevalent type of COI was financial (n = 26). Non-profit organizations funded 37.2% of the articles, while the sponsorship for 40.4% articles was unclear. Regression analysis showed that publications reporting COI had greater odds of receiving sponsorship from for-profit sources.

CONCLUSIONS

Sponsorship and COI information seem to be underreported in dental journals. Efforts should be made by authors, journals, and publishers to provide more comprehensive information to allow the reader to understand the potential impact of sponsorship and COI on study results.

CLINICAL SIGNIFICANCE

The underreporting of COI and sponsorship in dental articles hinders the interpretation of findings by readers. The results of the present study bring attention to this important topic as well as guide further improvements on the reporting of COI and sponsorship in dental articles.

Relationship Between Declarations of Conflict of Interests and Reporting Positive Outcomes in Iranian Dental Journals

Conflict of interests is a situation when someone is in need of other people's trust on one the hand and has personal or general interests on the other hand, resulting in conflict with the given responsibility. In this research work, an attempt was made to find the relation between declarations of conflict of interests and reporting positive outcomes in the dental journals in Iran (2000-2016). In this analytical/cross-sectional study, first Health and Biomedical Information was searched and all the Persian and English dental journals published in Iran were collected. Then, all the papers published in the journals from December 2000 to December 2016 were collected and categorized in terms of the year of publication, author or authors' affiliations, Persian and English journal, type of the substance or the drug used (including the manufacturing company), declarations of conflict of interests and the positive or negative conclusion of the report. Data were analyzed with the Fisher's exact test and Chi squared test, using the program SPSS 18. In numerical analysis, the significance was set at P < 0.05. Seventeen dental journals in Persian and English were analyzed: 10 in English and 7 in Persian. Reviewing these studies showed that of 1021 articles in Persian, in 128 cases there was no mention of a declaration of conflict of interests and in 11 cases, the COI had been stated. In addition, from 1220 articles in English, in 825 cases there was no mention of declarations of conflict of interests and in 45 cases, the declarations of COI had been mentioned. There was no significant relation between the COI and 'no' COI and the reporting of positive outcomes in papers in Iranian dental journals in terms of the journal type, year of publication and the journals' guarantee form (P = 0.25, P = 0.41 and P = 0.09). A total of 83% of studies with declarations of COI had one positive outcome, with a significant relationship in this field; however, in 73% of studies with no COI, there was one positive outcome, too. In general, the society expects that doctors would not consider any incentives except the health of the patients in the efforts made by them. The severity of the consequences of COI is of higher value when the patients' health is endangered due to it. In addition, COI might change the attitude and approach of other doctors and peers.

Conflicts of interest disclosure policies among Chinese medical journals: A cross-sectional study

IMPORTANCE

Conflicts of interest (COI) disclosure policies are critical to enhancing the integrity of research. However, it is unclear how Chinese medical journals interpret and enforce such policies.

OBJECTIVES

The goal of this investigation is to determine the current status of COI disclosure policy enforcement in Chinese medical journals and to promote comprehensive COI policies.

METHODS

In this cross-sectional study conducted from September 1st to October 29th 2017, journal instructions, websites and print issues of journals indexed by the Core Journals of China (version 2014), in the medical and health sector, were reviewed to identify whether COI disclosure policies existed and how complete these policies were.

RESULTS

Of 248 eligible journals, 78 (31%) mentioned COI policies; 9 (4%) applied standardized disclosure forms; 18 (7%) required disclosure statements in articles; 4 (2%) mentioned policy bases; none validated disclosed COIs; 2 (1%) mentioned how they dealt with breaches; 18 (7%) involved the management of disclosed COIs; and 62 (25%) and 55 (22%) noted financial and nonfinancial COIs, respectively. Seventy-eight journals (31%) mentioned COIs in research and authors' obligation towards disclosure; 2 (1%) and 6 (2%) mentioned family members' and institutional COIs, respectively. Twenty-two and 11 journals mentioned at least one form of financial and nonfinancial COI type in research, respectively. Seven journals (3%) required disclosure of the source of financial support in research, but no journals mentioned the amount of support. Seven (3%) and 12 (5%) journals mentioned COIs in the editorial process and peer-review, respectively. Clinical journals (45%) paid more attention to COI policies than non-clinical journals.

CONCLUSIONS

Approximately one-third of Chinese medical journals had COI policies, and of the journals that mentioned financial COIs most required nonfinancial COIs. However, the extent to which journals implemented COI policies was insufficient. There is a generic lack of standardized disclosure forms and management of COIs in most journals. The subject and details of COIs involved in the editorial and peer-review process received less attention than those in research.

Undisclosed conflicts of interest among biomedical textbook authors

BACKGROUND

Textbooks are a formative resource for health care providers during their education and are also an enduring reference for pathophysiology and treatment. Unlike the primary literature and clinical guidelines, biomedical textbook authors do not typically disclose potential financial conflicts of interest (pCoIs). The objective of this study was to evaluate whether the authors of textbooks used in the training of physicians, pharmacists, and dentists had appreciable undisclosed pCoIs in the form of patents or compensation received from pharmaceutical or biotechnology companies.

METHODS

The most recent editions of six medical textbooks, Harrison's Principles of Internal Medicine (_HarPIM), Katzung and Trevor's Basic and Clinical Pharmacology (_KatBCP), the American Osteopathic Association's Foundations of Osteopathic Medicine (_AOAFOM), Remington: The Science and Practice of Pharmacy (_RemSPP), Koda-Kimble and Young's Applied Therapeutics (_KKYAT), and Yagiela's Pharmacology and Therapeutics for Dentistry (_YagPTD), were selected after consulting biomedical educators for evaluation. Author names (N = 1,152, 29.2% female) were submitted to databases to examine patents (Google Scholar) and compensation (ProPublica's Dollars for Docs [PDD]).

RESULTS

Authors were listed as inventors on 677 patents (maximum/author = 23), with three-quarters (74.9%) to _HarPIM authors. Females were significantly underrepresented among patent holders. The PDD 2009-2013 database revealed receipt of US$13.2 million, the majority to (83.9%) to _HarPIM. The maximum compensation per author was $869,413. The PDD 2014 database identified receipt of $6.8 million, with 50.4% of eligible authors receiving compensation. The maximum compensation received by a single author was $560,021. Cardiovascular authors were most likely to have a PDD entry and neurologic disorders authors were least likely.

CONCLUSION

An appreciable subset of biomedical authors have patents and have received remuneration from medical product companies and this information is not disclosed to readers. These findings indicate that full transparency of financial pCoI should become a standard practice among the authors of biomedical educational materials.

Requirements of health policy and services journals for authors to disclose financial and non-financial conflicts of interest: a cross-sectional study

BACKGROUND

The requirements of the health policy and services journals for authors to report their financial and non-financial conflicts of interest (COI) are unclear. The present article aims to assess the requirements of health policy and services journals for authors to disclose their financial and non-financial COIs.

METHODS

This is a cross-sectional study of journals listed by the Web of Science under the category of 'Health Policy and Services'. We reviewed the 'Instructions for Authors' on the journals' websites and then simulated the submission of a manuscript to obtain any additional relevant information made available during that step. We abstracted data in duplicate and independently using a standardised form.

RESULTS

Out of 72 eligible journals, 67 (93%) had a COI policy. A minority of policies described how the disclosed COIs of authors would impact the editorial process (34%). None of the policies had clear-cut criteria for rejection based on the content of the disclosure. Approximately a fifth of policies (21%) explicitly stated that inaccurate or incomplete disclosures might lead to manuscript rejection or retraction. No policy described whether the journal would verify the accuracy or completeness of authors' disclosed COIs. Most journals' policies (93%) required the disclosure of at least one form of financial COI. While the majority asked for specification of source of payment (71%), a minority asked for the amount (18%). Overall, 81% of policies explicitly required disclosure of non-financial COIs.

CONCLUSION

A majority of health policy and services journal policies required the disclosure of authors' financial and non-financial COIs, but few required details on disclosed COIs. Health policy journals should provide specific definitions and instructions for disclosing non-financial COIs. A framework providing clear typology and operational definitions of the different types of COIs will facilitate both their disclosure by authors and reviewers and their assessment and management by the editorial team and the readers.

Industry sponsorship and research outcome

BACKGROUND

Clinical research affecting how doctors practice medicine is increasingly sponsored by companies that make drugs and medical devices. Previous systematic reviews have found that pharmaceutical-industry sponsored studies are more often favorable to the sponsor's product compared with studies with other sources of sponsorship. A similar association between sponsorship and outcomes have been found for device studies, but the body of evidence is not as strong as for sponsorship of drug studies. This review is an update of a previous Cochrane review and includes empirical studies on the association between sponsorship and research outcome.

OBJECTIVES

To investigate whether industry sponsored drug and device studies have more favorable outcomes and differ in risk of bias, compared with studies having other sources of sponsorship.

SEARCH METHODS

In this update we searched MEDLINE (2010 to February 2015), Embase (2010 to February 2015), the Cochrane Methodology Register (2015, Issue 2) and Web of Science (June 2015). In addition, we searched reference lists of included papers, previous systematic reviews and author files.

SELECTION CRITERIA

Cross-sectional studies, cohort studies, systematic reviews and meta-analyses that quantitatively compared primary research studies of drugs or medical devices sponsored by industry with studies with other sources of sponsorship. We had no language restrictions.

DATA COLLECTION AND ANALYSIS

Two assessors screened abstracts and identified and included relevant papers. Two assessors extracted data, and we contacted authors of included papers for additional unpublished data. Outcomes included favorable results, favorable conclusions, effect size, risk of bias and whether the conclusions agreed with the study results. Two assessors assessed risk of bias of included papers. We calculated pooled risk ratios (RR) for dichotomous data (with 95% confidence intervals (CIs)).

MAIN RESULTS

Twenty-seven new papers were included in this update and in total the review contains 75 included papers. Industry sponsored studies more often had favorable efficacy results, RR: 1.27 (95% CI: 1.17 to 1.37) (25 papers) (moderate quality evidence), similar harms results RR: 1.37 (95% CI: 0.64 to 2.93) (four papers) (very low quality evidence) and more often favorable conclusions RR: 1.34 (95% CI: 1.19 to 1.51) (29 papers) (low quality evidence) compared with non-industry sponsored studies. Nineteen papers reported on sponsorship and efficacy effect size, but could not be pooled due to differences in their reporting of data and the results were heterogeneous. We did not find a difference between drug and device studies in the association between sponsorship and conclusions (test for interaction, P = 0.98) (four papers). Comparing industry and non-industry sponsored studies, we did not find a difference in risk of bias from sequence generation, allocation concealment, follow-up and selective outcome reporting. However, industry sponsored studies more often had low risk of bias from blinding, RR: 1.25 (95% CI: 1.05 to 1.50) (13 papers), compared with non-industry sponsored studies. In industry sponsored studies, there was less agreement between the results and the conclusions than in non-industry sponsored studies, RR: 0.83 (95% CI: 0.70 to 0.98) (six papers).

AUTHORS' CONCLUSIONS

Sponsorship of drug and device studies by the manufacturing company leads to more favorable efficacy results and conclusions than sponsorship by other sources. Our analyses suggest the existence of an industry bias that cannot be explained by standard 'Risk of bias' assessments.

A Quantitative Analysis of Undisclosed Conflicts of Interest in Pharmacology Textbooks

BACKGROUND

Disclosure of potential conflicts of interest (CoI) is a standard practice for many biomedical journals but not for educational materials. The goal of this investigation was to determine whether the authors of pharmacology textbooks have undisclosed financial CoIs and to identify author characteristics associated with CoIs.

METHODS AND FINDINGS

The presence of potential CoIs was evaluated by submitting author names (N = 403; 36.3% female) to a patent database (Google Scholar) as well as a database that reports on the compensation ($USD) received from 15 pharmaceutical companies (ProPublica's Dollars for Docs). All publications (N = 410) of the ten highest compensated authors from 2009 to 2013 and indexed in Pubmed were also examined for disclosure of additional companies that the authors received research support, consulted, or served on speaker's bureaus. A total of 134 patents had been awarded (Maximum = 18/author) to textbook authors. Relative to DiPiro's Pharmacotherapy: A Pathophysiologic Approach, contributors to Goodman and Gilman's Pharmacological Basis of Therapeutics and Katzung's Basic and Clinical Pharmacology were more frequently patent holders (OR = 6.45, P < .0005). Female authors were less likely than males to have > 1 patent (OR = 0.15, P < .0005). A total of $2,411,080 USD (28.3% for speaking, 27.0% for consulting, and 23.9% for research), was received by 53 authors (Range = $299 to $310,000/author). Highly compensated authors were from multiple fields including oncology, psychiatry, neurology, and urology. The maximum number of additional companies, not currently indexed in the Dollars for Docs database, for which an author had potential CoIs was 73.

CONCLUSIONS

Financial CoIs are common among the authors of pharmacology and pharmacotherapy textbooks. Full transparency of potential CoIs, particularly patents, should become standard procedure for future editions of educational materials in pharmacology.

An overview of characteristics of registered studies on dental implants

OBJECTIVE

Clinical trials serve as the empirical basis for clinical decision making. The objective of the current study is to provide an overview of clinical trials examining dental implant outcomes.

METHOD

All registered studies on Dental Implants were selected for analysis. The clinicaltrials.gov<http://clinicaltrials.gov/> website was used to query the characteristics of registered studies. The search term used was dental implants.

RESULTS

As of the study conduct date (01/01/2014), a total of 205 studies on dental implants were registered. These included 168 interventional and 37 observational studies. Results were available for only 14 studies. All observational studies and 98.8% of interventional studies included both male and female subjects. Close to 60% of studies had sample sizes between 1 and 50. NIH was listed as funding source in only 5 interventional studies and 3 observational studies. 80% of interventional studies were randomized. However, double masking was reported in only 15% of interventional studies with majority being open labeled.

CONCLUSION

ClinicalTrials.gov registry was created with the intention of increasing the transparency of conducted or ongoing clinical studies and to minimize publication bias commonly seen with industry-sponsored studies. Results of the current study showed that a predominating number of registered studies are funded by industry and other sources, very few registered studies have made their results public, and the ClinicalTrials.gov registry does not provide sufficient information on the quality of study design and thus precluding the public and researchers to judge on the quality of registered studies and publication bias.

Systematic review of short- (5-10 years) and long-term (10 years or more) survival and success of full-arch fixed dental hybrid prostheses and supporting implants

OBJECTIVES

The aim of this systematic review was to investigate the short-term (5-10 year mean follow-up) and long-term (10 year or more) survival and success of fixed full arch dental hybrid prosthesis and supporting dental implants.

METHODS

Studies reporting interventions with full-arch fixed dental hybrid prostheses were identified by searching PubMed/Medline (NCBI), Web of Science (Thomson Reuters), the Cochrane Register of Controlled Clinical Trials (EBSCO), and Dentistry and Oral Sciences Source (DOSS; EBSCO) from the earliest available dates through July 17, 2013. Through a series of review process by two examiners, potentially qualifying studies were identified and assessed with respect to the inclusion criteria.

RESULTS

A total of 18 studies were included for the quality assessment and the systematic review. Within the limitation of available studies, high short-term survival rates of full arch fixed dental hybrid prostheses (93.3-100%) and supporting implants (87.89-100%) were found. However, the availability of studies investigating long-term outcomes seemed scarce. Furthermore, the included studies were subjected to potential sources of bias (i.e. publication, reporting, attrition bias).

CONCLUSIONS

Despite seemingly high short-term survival, long-term survival of implant supported full arch fixed dental hybrid prosthesis could not be determined due to limited availability of true long-term studies. Although it may be a valuable option for a patient with a completely edentulous ridge(s), the strategic removal of teeth with satisfactory prognosis for the sake of delivering an implant supported full-arch dental hybrid prosthesis should be avoided.