Discrepancies between Abstracts Presented at International Association for Dental Research Annual Sessions from 2004 to 2005 and Full-Text Publication

Reporting inconsistency between published conference abstracts and article abstracts of randomised controlled trials in prosthodontics presented at IADR general sessions

Background

There is commonly a discrepancy between conference abstracts and published article abstracts in prosthodontic randomized controlled trials (RCTs), which may mislead the scholars those attend conferences.

Objective

To identify the characteristics predicting inconsistency between conference abstracts and published article abstracts in prosthodontic RCTs.

Methods

The conference abstracts of prosthodontic RCTs presented at the IADR general sessions from 2002 to 2015 were searched. Electronic searches of MEDLINE, EMBASE, the Cochrane Library, and Google Scholar databases were conducted to match full-text publications for conference abstracts. Two investigators extracted basic characteristics and assessed the consistency and reporting quality independently and in duplicate. The linear regression model was used to analyze the predictors of inconsistency.

Results

A total of 147 conference abstracts were matched with published articles. Results for the secondary outcome measure, Statistical analysis, and precision measure were less than 50% consistent, and even nearly 5% of the studies had opposite conclusions. Multiple linear regression analysis showed that three factors were correlated with lower inconsistency, including continent of origin (p = 0.011), presentation type (p = 0.017), and difference in reporting quality (p = 0.013).

Conclusion

Conference attendees should cautiously treat the findings of the conference abstracts. Researchers should improve the precision of the information delivered at conferences. We recommend the authors of RCTs to explain the primary difference between conference abstracts and article abstracts.

Publication outcome of research presented at the European Congress of Endocrinology: a web scraping-based analysis and critical appraisal

PURPOSE

The current study aimed to determine the publication outcome of abstracts presented at the 16th European Congress of Endocrinology (ECE 2014).

METHODS

All presentations were collected with the web scraping - Python coding from the official website and converted into Google Scholar and PubMed search links with coding. A particular interface was coded to evaluate the results. An online survey was sent to the authors to assess the impact of congress on their publication.

RESULTS

A total of 1205 abstracts from 71 countries were featured at the congress of which, 1145 (95%) were poster presentations (PP), and 60 (5%) were oral presentations. Subsequently, 341 abstracts (28.3%) were published as a full paper. There was no major change from the abstract in 73.3% of full articles whereas 68.9% had at least one minor change. OP had higher conversion rates to publication than PP (65% vs 26.4; p = 0.01) and a higher median number of citations than PP (12 vs 6; p = 0.01). The median time to publication was 12 months (IQR: 2-24 months). OP was published in journals with a higher median impact factor (IF) than PP (5 vs 2.94; p = 0.01). Multi-country collaborative studies turned into more publications than single-country studies (OR: 3.91 95% CI: 2.52-6.06; p < 0.01). The congress's potential IF was calculated as 3.18. Among the authors responded to survey, 95% indicated that presenting at the congress was valuable for preparation of their publication.

CONCLUSIONS

This first study evaluating the publication outcome of an international endocrinology congress suggests a 28.3% publication ratio with low discrepancy and 3.18 IF for ECE 2014.

Abstracts presented at the European Association for Osseointegration (EAO) Congresses: Publication fate and discrepancies with full-length articles

OBJECTIVES

To investigate the full publication proportion (FPP) of abstracts presented at the 2010 and 2011 EAO Congresses, analyse the discrepancies between abstracts and their full publications, and explore potential predictors of FPP and discrepancies.

METHODS

Abstracts presented at the 2010 and 2011 EAO Congresses were retrieved. Associated full publications were identified by searching PubMed, Embase and Google Scholar. Discrepancies between abstracts and full publications were identified, classified and evaluated using a discrepancy score. The Kaplan-Meier survival analysis was used to describe cumulative FPP over time. Predictors for FPP and the discrepancy score were analysed using cox regression modelling and a linear regression model, respectively.

RESULTS

850 abstracts were included. The overall FPP was 36.4% with a median time lapse of 12 months. Higher FPP were significantly associated with oral presentation (HR=2.33; 95% CI: 1.68 to 3.22; p<0.001), multiple affiliations (HR =1.32; 95% CI: 1.00 to 1.73; p=0.048) and presence of statistical tests (HR =1.78; 95% CI: 1.36 to 2.32; p<0.001). 91.3% pairs had at least one minor change from the abstract and 70.9% had at least one major change. Greater discrepancy score was significantly associated with longer time lapse (B=0.06; 95% CI: 0.04 to 0.08; p<0.001) and being clinical research (B=1.30; 95% CI: 0.52 to 2.08; p=0.001).

CONCLUSIONS

Thirty-six percent of abstracts presented at the EAO Congresses were published. Among these, more than two-thirds showed at least one major change in their full publications. Abstracts presented in oral implantology conferences should not be relied upon to inform practice.

Full publication of results initially presented in abstracts

BACKGROUND

Abstracts of presentations at scientific meetings are usually available only in conference proceedings. If subsequent full publication of results reported in these abstracts is based on the magnitude or direction of the results, publication bias may result. Publication bias creates problems for those conducting systematic reviews or relying on the published literature for evidence about health and social care.

OBJECTIVES

To systematically review reports of studies that have examined the proportion of meeting abstracts and other summaries that are subsequently published in full, the time between meeting presentation and full publication, and factors associated with full publication.

SEARCH METHODS

We searched MEDLINE, Embase, the Cochrane Library, Science Citation Index, reference lists, and author files. The most recent search was done in February 2016 for this substantial update to our earlier Cochrane Methodology Review (published in 2007).

SELECTION CRITERIA

We included reports of methodology research that examined the proportion of biomedical results initially presented as abstracts or in summary form that were subsequently published. Searches for full publications had to be at least two years after meeting presentation.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data and assessed risk of bias. We calculated the proportion of abstracts published in full using a random-effects model. Dichotomous variables were analyzed using risk ratio (RR), with multivariable models taking into account various characteristics of the reports. We assessed time to publication using Kaplan-Meier survival analyses.

MAIN RESULTS

Combining data from 425 reports (307,028 abstracts) resulted in an overall full publication proportion of 37.3% (95% confidence interval (CI), 35.3% to 39.3%) with varying lengths of follow-up. This is significantly lower than that found in our 2007 review (44.5%. 95% CI, 43.9% to 45.1%). Using a survival analyses to estimate the proportion of abstracts that would be published in full by 10 years produced proportions of 46.4% for all studies; 68.7% for randomized and controlled trials and 44.9% for other studies. Three hundred and fifty-three reports were at high risk of bias on one or more items, but only 32 reports were considered at high risk of bias overall.Forty-five reports (15,783 abstracts) with 'positive' results (defined as any 'significant' result) showed an association with full publication (RR = 1.31; 95% CI 1.23 to 1.40), as did 'positive' results defined as a result favoring the experimental treatment (RR =1.17; 95% CI 1.07 to 1.28) in 34 reports (8794 abstracts). Results emanating from randomized or controlled trials showed the same pattern for both definitions (RR = 1.21; 95% CI 1.10 to 1.32 (15 reports and 2616 abstracts) and RR = 1.17; 95% CI, 1.04 to 1.32 (13 reports and 2307 abstracts), respectively.Other factors associated with full publication include oral presentation (RR = 1.46; 95% CI 1.40 to 1.52; studied in 143 reports with 115,910 abstracts); acceptance for meeting presentation (RR = 1.65; 95% CI 1.48 to 1.85; 22 reports with 22,319 abstracts); randomized trial design (RR = 1.51; 95% CI 1.36 to 1.67; 47 reports with 28,928 abstracts); and basic research (RR = 0.78; 95% CI 0.74 to 0.82; 92 reports with 97,372 abstracts). Abstracts originating at an academic setting were associated with full publication (RR = 1.60; 95% CI 1.34 to 1.92; 34 reports with 16,913 abstracts), as were those considered to be of higher quality (RR = 1.46; 95% CI 1.23 to 1.73; 12 reports with 3364 abstracts), or having high impact (RR = 1.60; 95% CI 1.41 to 1.82; 11 reports with 6982 abstracts). Sensitivity analyses excluding reports that were abstracts themselves or classified as having a high risk of bias did not change these findings in any important way.In considering the reports of the methodology research that we included in this review, we found that reports published in English or from a native English-speaking country found significantly higher proportions of studies published in full, but that there was no association with year of report publication. The findings correspond to a proportion of abstracts published in full of 31.9% for all reports, 40.5% for reports in English, 42.9% for reports from native English-speaking countries, and 52.2% for both these covariates combined.

AUTHORS' CONCLUSIONS

More than half of results from abstracts, and almost a third of randomized trial results initially presented as abstracts fail to be published in full and this problem does not appear to be decreasing over time. Publication bias is present in that 'positive' results were more frequently published than 'not positive' results. Reports of methodology research written in English showed that a higher proportion of abstracts had been published in full, as did those from native English-speaking countries, suggesting that studies from non-native English-speaking countries may be underrepresented in the scientific literature. After the considerable work involved in adding in the more than 300 additional studies found by the February 2016 searches, we chose not to update the search again because additional searches are unlikely to change these overall conclusions in any important way.

Timing of publication of abstracts of randomized controlled trials presented in congresses: The example of the European League against Rheumatism meeting

INTRODUCTION

The EUropean League Against Rheumatism (EULAR) congress is an important meeting to present abstracts of research in rheumatology. However, information in these abstracts is insufficient and must be followed and developed in a published article. This study aims to assess to what extent abstracts presented in the EULAR Meeting are published in journals.

METHODS

We identified all abstracts of randomized controlled trials accepted for presentation at the EULAR annual meeting from 2002 to 2011. Using a standardized research, we used Pubmed to find the corresponding publication to each congress abstract. We assessed the cumulative percentage of published abstracts over time and compared the number of included patients, the outcome and the moment of outcome assessment between abstracts presented in congress and in published article.

RESULTS

A total of 1839 abstracts were analyzed. The cumulative probability of abstracts being published in journals was 16.9% (95% CI: 15.2% to 18.6%) at 12 months, 34.3% (95% CI: 32.2% to 36.5%) at 24 months, and 46.5% (95% CI: 44.2% to 48.8%) at 36 months. When evaluable, a difference between the congress and published abstracts was found in 29.0% (247/852). The most frequent difference was a different number of included patients (196/247: 79.4%).

CONCLUSION

More than half of the abstracts of randomized trials were not published three years after they were presented in EULAR meeting. Thirty percent of abstracts were different between their presented and published version.

Discrepancies Between Plastic Surgery Meeting Abstracts and Subsequent Full-Length Manuscript Publications

BACKGROUND

The purpose of this bibliometric study was to assess the discrepancies between plastic surgery meeting abstracts and subsequent full-length manuscript publications.

METHODS

Abstracts presented at the Brazilian Congress of Plastic Surgery from 2010 to 2011 were compared with matching manuscript publications. Discrepancies between the abstract and the subsequent manuscript were categorized as major (changes in the purpose, methods, study design, sample size, statistical analysis, results, and conclusions) and minor (changes in the title and authorship) variations.

RESULTS

The overall discrepancy rate was 96 %, with at least one major (76 %) and/or minor (96 %) variation. There were inconsistencies between the study title (56 %), authorship (92 %), purpose (6 %), methods (20 %), study design (36 %), sample size (51.2 %), statistical analysis (14 %), results (20 %), and conclusions (8 %) of manuscripts compared with their corresponding meeting abstracts.

CONCLUSION

As changes occur before manuscript publication of plastic surgery meeting abstracts, caution should be exercised in referencing abstracts or altering surgical practices based on abstracts' content.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

ClinicalTrials.gov registration can supplement information in abstracts for systematic reviews: a comparison study

Background

The inclusion of randomized controlled trials (RCTs) reported in conference abstracts in systematic reviews is controversial, partly because study design information and risk of bias is often not fully reported in the abstract. The Association for Research in Vision and Ophthalmology (ARVO) requires trial registration of abstracts submitted for their annual conference as of 2007. Our goal was to assess the feasibility of obtaining study design information critical to systematic reviews, but not typically included in conference abstracts, from the trial registration record.

Methods

We reviewed all conference abstracts presented at the ARVO meetings from 2007 through 2009, and identified 496 RCTs; 154 had a single matching registration record in ClinicalTrials.gov. Two individuals independently extracted information from the abstract and the ClinicalTrials.gov record, including study design, sample size, inclusion criteria, masking, interventions, outcomes, funder, and investigator name and contact information. Discrepancies were resolved by consensus. We assessed the frequencies of reporting variables appearing in the abstract and the trial register and assessed agreement of information reported in both sources.

Results

We found a substantial amount of study design information in the ClinicalTrials.gov record that was unavailable in the corresponding conference abstract, including eligibility criteria associated with gender (83%; 128/154); masking or blinding of study participants (53%, 82/154), persons administering treatment (30%, 46/154), and persons measuring the outcomes (40%, 61/154)); and number of study centers (58%; 90/154). Only 34% (52/154) of abstracts explicitly described a primary outcome, but a primary outcome was included in the “Primary Outcome” field in the ClinicalTrials.gov record for 82% (126/154) of studies. One or more study interventions were reported in each abstract, but agreed exactly with those reported in ClinicalTrials.gov only slightly more than half the time (88/154, 56%). We found no contact information for study investigators in the abstract, but this information was available in less than one quarter of ClinicalTrial.gov records (17%; 26/154).

Conclusion

RCT design information not reported in conference abstracts is often available in the corresponding ClinicalTrials.gov registration record. Sometimes there is conflicting information reported in the two sources and further contact with the trial investigators may still be required.