Abstract

Introduction

Science has long faced problems with publication bias, with concerns being raised in the past few years about its increasing occurrence.¹1. Fanelli D. Negative results are disappearing from most disciplines and countries. Scientometrics. 2012 Mar;90(3):891-904. Even as early as 1959, 97% of the published papers presented positive results,²2. Sterling TD. Publication decisions and their possible effects on inferences drawn from tests of significance - or vice versa. J Am Stat Assoc. 1959 Mar;54(285):30-4. one characteristic of publication bias. In 1995, the same author observed that practices leading to publication bias had not changed over 36 years.³3. Sterling TD, Rosenbaum WL, Weinkam JJ. Publication decisions revisited - the effect ofthe outcome of statistical tests on the decision to publish and vice-versa. Am Stat. 1995 Feb;49(1):108-12.

Publication bias might occur during different phases of research. Initially, scientists are not encouraged to report non-significant or negative results, as studies with positive results have higher chances of being published,⁴4. Crawford JM, Briggs CL, Engeland CG. Publication bias and its implications for evidence-based clinical decision making. J Dent Educ. 2010 Jun;74(6):593-600.^,55. Dwan K, Altman DG, Arnaiz JA, Bloom J, Chan AW, Cronin E, et al. Systematic review of the empirical evidence of study publication bias and outcome reporting bias. PLoS One. 2008 Aug;3(8):e3081.^,66. Polychronopoulou A, Pandis N, Eliades T. Assessment of publication bias in dental specialty journals. J Evid Based Dent Pract. 2010 Dec;10(4):207-11. despite the fact that many of these unpublished studies might have required investments of time or effort that may be repeated by another researcher with no access to these outcomes. In addition to research resources, animals or human beings might have contributed to this knowledge without recognition. This issue should be of concern to the scientific community, yet little attention is focused towards it. After submission, editors and reviewers are also more prone to accept studies that present positive results. Interestingly, a recent investigation presented two papers with identical methods but different outcomes – positive or negative – to two groups of reviewers.⁷7. Emerson GB, Warme WJ, Wolf FM, Heckman JD, Brand RA, Leopold SS. Testing for the presence of positive-outcome bias in peer review: a randomized controlled trial. Arch Intern Med. 2010 Nov;170(21):1934-9. Participants in the positive outcome group not only gave higher priority to the publication of the findings, but also rated the methods section significantly better. In addition, industry-related outcomes are associated with the publication of pro-industry results.⁸8. Ridker PM, Torres J. Reported outcomes in major cardiovascular clinical trials funded by for-profit and not-for-profit organizations: 2000-2005. JAMA. 2006 May;295(19):2270-4.^,99. Bekelman JE, Li Y, Gross CP. Scope and impact of financial conflicts of interest in biomedical research: a systematic review. JAMA. 2003 Jan;289(4):454-65. Based on these outcome-related issues, a few authors have suggested a different submission process divided in two steps: the first presenting only introduction and methods and the second one with outcomes and discussion.¹⁰10. Smulders YM. A two-step manuscript submission process can reduce publication bias. J Clin Epidemiol. 2013 Sep;66(9):946-7.^,1111. Newcombe RG. Towards a reduction in publication bias. Br Med J. 1987 Sep;295(6599):656-9. The first step would be much more important than the second, and studies would be assessed for their approach and design rather than their results.

The fact that editorial board members of a journal have a better chance of publishing in their board journals occurs in at least five medical specialties, with journals almost three times more likely to publish reports from their own editorial board than from one of the competing journals within their subspecialty.¹²12. Luty J, Arokiadass SM, Easow JM, Anapreddy JR. Preferential publication of editorial board members in medical specialty journals. J Med Ethics. 2009 Mar;35(3):200-2. One may argue, however, that this publication rate naturally results from populating an editorial board with a team of specialty experts. Editorial board members may also preferentially submit their research reports to their own journal. No studies, to our knowledge, have assessed this issue in major oral health journals. Therefore, the aim of this study was to determine the participation rate of editorial board members in publications from their board journals, as well as other associated variables.

Methodology

Journal selection

Journals were selected based on the 5-year impact factor as provided by the Journal of Citation Reports (JCR) 2012. The ten highest-ranked journals under the ‘Dentistry, Oral Surgery & Medicine’ subject category were evaluated: Clinical Oral Implants Research (COIR), Journal of Clinical Periodontology (JCP), Clinical Implant Dentistry and Related Research (CIDRR), Periodontology 2000 (Perio 2000), Journal of Dental Research (JDR), Dental Materials, Oral Oncology, International Oral and Maxillofacial Implants (IOMI), Journal of Dentistry (JDent), and Community Dentistry and Oral Epidemiology (CDOE). Publication data was analyzed for 2010, 2011, and 2012.

Data collection

All articles published in 2010, 2011, and 2012 were considered, but only original research reports were included in the statistical analyses. Each published issue and article was evaluated manually by one of the authors. Research reports that included a member of the editorial board as an author were scored and considered for later analysis. If the paper had two or more editorial members as co-authors the unit was still counted only once.

Statistical analysis

The primary outcome of the present study was the number of articles published with editorial board members as authors. Independent variables included the total number of editorial board members, the total number of articles published in each year, and the impact factor. Descriptive statistics were calculated separately for each year. The impact factor was dichotomized into <4.0 and ≥4.0. The number of editorial board members and the total number of published articles in a year were analyzed as count variables using 10 units of change to allow for easier interpretation of coefficients.

The association between the number of articles with editorial board members as authors and the three independent variables was assessed using generalized estimating equations (GEE) with Poisson distribution, log link, and exchangeable correlation. Bivariate models were fitted in a first-step analysis, with year as a covariate. The final main-effects multiple model was fitted with all variables and the year. Incidence rate ratios (IRR) and 95% confidence intervals (95% CI) are reported. Statistical analyses were performed using Stata 12 software (StataCorp., College Station, USA). The significance level was set at 5%.

Results

Table 1 presents the detailed information of the surveyed journals over the three years evaluated. The journal impact factor varied between 2.948 and 4.560, and the mean number of editorial board members was 54.7 (standard deviation 30.2; range 4 to 102). Overall, there was an increase in the average number of articles published from 2010 (115.2 ± 52.2) to 2012 (134.7 ± 47.4). The number and percentage of articles published with editorial board members as authors over the three years did not follow the same pattern, with a slight decrease from 2010 to 2011 and an increase in 2012. Over all three years, Clinical Implant Dentistry and Related Research had the highest percentage of articles published with editorial board members (50.3%) followed by Dental Materials (41.9%). The International Journal of Oral and Maxillofacial Implants had the lowest percentage (3.8%).

The number of articles with editorial board members as authors was statistically higher for journals with impact factors ≥4.0 across all three years (Figure 1). The analysis of predictors of the number of articles with editorial board members as authors is presented in Table 2. In the first step, three separate models were fitted adjusting for the year of publication, with impact factor, number of editorial board members, and total number of articles published significantly associated with the number of articles with editorial members. In the final multiple model that included all variables and year of publication, the three predictors remained significantly associated with the outcome. The rate of the number of articles published with editorial members as authors was approximately two times higher (IRR=2.34) for journals with impact factors ≥4.0 compared to those with factors <4.0. This rate significantly increased at a similar magnitude for each 10 editorial board members and 10 published articles (10% and 7% increase, respectively).

Discussion

The present study assessed publication by editorial board members in oral health journals. Around one-third of the articles published in the ten major oral health journals had at least one author that is a member of the editorial board, a consistent level over the past three years. Moreover, journals with higher impact factors were more likely to have articles with editorial board members as authors. The rate of article authorship by editorial members also increased with larger total numbers of published articles and the number of members on the editorial board.

One explanation for this outcome is preferential publication, as the odds of an editorial board member having his/her article published could be as much as 3 times higher.¹²12. Luty J, Arokiadass SM, Easow JM, Anapreddy JR. Preferential publication of editorial board members in medical specialty journals. J Med Ethics. 2009 Mar;35(3):200-2. Alternatively, editorial board members might be more prone to submit papers to their journal as they are certain of the journal’s scope and quality. Editorial board members of high-impact journals are chosen because of their expertise in the field, and therefore need to publish their own research, so they may be more prolific than other authors. Editorial board members might also expect a friendlier peer-review process when submitting their manuscripts to their own journals. Data for rejected papers in each journal would be important for understanding this outcome, but this information is not accessible to the public.

We used the 5-year impact factor published in 2013 in the Journal of Citation Reports to select publications. The editorial board members may vary from year to year, but we only used the board member list from 2013 for all years. To avoid increasing the odds of participation of editorial board members, we only included papers classified as original research and excluded guest editorials, invited reviews, and other similar articles.

Editorial board size varied significantly between journals, and board size was a predictor for higher number of articles with an editorial board member as author or co-author. There are no established standards for board size, although the data does suggest that larger boards would have more self-published articles in the journal. This kind of decision is made by the publishers considering the peculiarities of the journal and the need for contributions from editorial board members. Editorial boards should have specific functions for each member, and board size should reflect variables such as how many issues and volumes are published each year.

We also found that the contributions – papers published – were not homogenous across board members, with each journal having some members that had more publications in their board journals than others. This fact, however, might be influenced by the editorial policy of each journal, and was not analyzed here. Importantly, the majority of the higher impact journals do not use a blinded review process, where the authors frequently do not know who reviewed the manuscript but the referees know the authorship of the paper. This could be an explanation for our findings. Nevertheless, given that the choice of an editorial board member is based on his/her scientific contributions, they would logically be expected to have higher participation and publication rates for their own research.

Publication bias is a reality in science and the preferential publication of editorial board members could contribute to it. Therefore, editors must consistently examine the review process to make sure it is as fair as possible. Moreover, contemporary ethical practices would indicate that a high rate of publication by editorial board members in the oral health literature requires close observation, particularly for higher-impact journals with larger editorial boards. Editors should be aware of this fact to monitor the impact of this authorship pattern in possible publication bias.

Conclusion

Journals with a higher impact factor and larger editorial boards had a higher chance of editorial board members publishing in their board journals. Participation of editorial board members as authors in publishing varies significantly among journals.

References

Publication Dates

History