The purpose of this study was to determine the publication rate and time to publication following abstract presentation at a major neurosurgical meeting, namely the 2005 annual meeting of the Congress of Neurological Surgeons (CNS). We reviewed all 754 abstracts presented at the 2005 CNS annual meeting to determine publication status and identify factors that are associated with publication. A standardized database search was conducted to determine publication status. Predictors of publication were examined. Of the 754 abstracts presented, 383 (50.8%) were published after 5.3 years. The median time to publication was 450 days (range-646 to 1953 days) with 16% being published prior to the meeting. Oral presentations had a publication rate of 64.0% compared to 48.3% for poster presentations. Of the abstracts not published prior to the meeting, 77% were published within 3 years of the meeting. In univariate analysis, neuro-oncology abstracts (OR 1.88; 95% CI 1.34 - 2.64; p < 0.001) and abstracts selected for oral presentation (OR 1.97; 95% CI 1.30 - 2.99; p = 0.001) had a significantly higher likelihood of publication. These associations remained independent in multivariate analysis. Neuro-oncology abstracts (p = 0.004), basic science research (p = 0.003) and abstracts selected for oral presentation (p = 0.036) were published in higher impact factor journals. Half of presentations at the annual CNS meeting will be published in peer-reviewed journals with a median time to publication of 450 days. Neuro-oncology abstracts and those abstracts selected for oral presentation have a significantly higher likelihood of publication.
Attending and presenting abstracts at prominent neurosurgical meetings is an exciting and interactive opportunity to disseminate new ideas. However, these meeting abstracts may be incomplete summaries of preliminary data, for which access is effectively limited to those in attendance at the meeting and which are subject to an abbreviated, albeit, competitive peer-review process. Abstract presentation may influence clinical practice of clinicians in attendance but are not indexed in frequently used electronic databases. Therefore, abstracts which do not ultimately and in a timely fashion culminate in full-text publication may have a minimal impact on the neurosurgical community in general.
The publication rate following abstract presentation is one accepted indicator of conference quality. In non- neurosurgical fields the publication rate following abstract presentation ranges from 8% - 84% [
We reviewed all accepted and presented abstracts (n = 754) from the online abstract archive (http://w3.cns.org/university/abstracts/index2.asp) for the 55th annual meeting of the Congress of Neurological Surgeons (CNS) held October 8 - 13, 2005, in Boston, Massachusetts. Withdrawn (accepted, but not presented; n = 1) or duplicate abstracts (n = 1) were excluded.
Data extracted through abstract review included: neurosurgical subspecialty (vascular, neuro-oncology, spine, functional, peripheral nerve, neurotrauma, pediatrics, radiosurgery, general), country of origin of principal author, presentation type (oral vs. poster), research type (clinical vs. basic science), study design (according to epidemiological definitions), sample size, presence of statistically significant results (defined as p < 0.05), new technology or surgical technique, industry sponsorship and PhD listed by the principal investigator. Data abstraction was carried out by a single investigator and validated by a second investigator who reviewed randomly selected abstracts. Inconsistencies were resolved through consensus.
Similar to previous studies in non-neurosurgical fields publication status was determined using computerized database searches conducted independently by two investigators in MEDLINE, Scopus and Google Scholar [
The ISI Web of Knowledge citation database (Philadelphia, USA) was used to determine the 2010 impact factor for each journal. Publications in journals not indexed or in journals that did not have an impact factor listed were excluded from the analysis.
Categorical variables were compared using chi-square test. Continuous variables were reported as means with standard deviations or in the case of outliers as medians. Continuous variables were compared using the t test. To determine predictors of full-text publication, odds ratios and their corresponding 95% confidence intervals were calculated using univariate and multivariate logistic regression analysis. All statistical analyses were performed by using SPSS (version 18.0 for Windows).
At the 55th annual meeting of the CNS, 1134 abstracts were submitted for presentation, of which 755 were ultimately selected for presentation (personal communication, CNS). Of these 755 abstracts, which are available at the CNS online abstract archive (http://w3.cns.org/university/abstracts/index2.asp), one was withdrawn prior to the conference, resulting in 754 abstracts being included in this analysis.
Abstract characteristics are outlined in
Of the 754 abstracts presented at the 2005 CNS annual meeting 383 (50.8%) resulted in full-text publications at 5.3 years. Oral presentations had a publication rate of 64.0% (73/114) compared to 48.3% (308/638) for poster presentations. Interestingly, 16.2% (61) of abstracts were published prior to the meeting with 1.3% being published in the year prior to the conference (2004) before the abstract deadline. Of the articles that were not published prior to the meeting, most were published within two (57%) or three (77%) years, with a median time to publication of 450 days with a wide range; the earliest publication occurring 646 days prior to the conference and the latest occurring 1953 days after the conference (
Articles were published in 121 different journals with 236 (61.4%) of publications in dedicated neurosurgery journals and one-third of publication occurring in either Neurosurgery or the Journal of Neurosurgery. The top 8 journals in which publications occurred and their 2010 impact factors are listed in
Neuro-oncology abstracts had a significantly higher likelihood of publication with an odds ratio of 1.88 (95% CI 1.34 - 2.64; p < 0.001) relative to all other abstracts. Abstracts accepted for an oral presentation were also more frequently published compared to poster presentations (OR 1.91; 95% CI 1.26 - 2.88, p = 0.002). Although there was no statistically significant difference in publication rate between basic and clinical research, basic science
Characteristic | n (%) | Published, n (%) |
---|---|---|
Number of Abstracts | 754 | 383 (50.8) |
Presentation type | ||
Oral presentation | 114 (15.2) | 73 (64.0) |
Poster presentation | 638 (84.8) | 308 (48.3) |
Research type | ||
Clinical science | 601 (79.7) | 88 (57.5) |
Basic science | 153 (20.3) | 295 (49.1) |
Subspecialty | ||
Vascular | 138 (18.3) | 65 (47.1) |
Neuro-oncology | 184 (24.4) | 115 (62.5) |
Spine | 151 (20.0) | 64 (42.4) |
Functional | 61 (8.1) | 31 (50.8) |
Peripheral nerve | 13 (1.7) | 6 (46.2) |
Neurotrauma | 39 (5.2) | 21 (53.8) |
Pediatrics | 37 (4.9) | 21 (56.8) |
Radiosurgery | 26 (3.4) | 17 (65.4) |
General | 105 (13.9) | 43 (41.0) |
Country of Origin | ||
United States | 534 (70.8) | 274 (51.3) |
Canada | 31 (4.1) | 19 (61.3) |
Other | 189 (25.1) | 90 (47.6) |
Study Design | ||
Randomized Control Trial | 17 (2.3) | 10 (58.8) |
Cohort Study | 381 (50.5) | 193 (50.7) |
Case-control study | 48 (6.4) | 26 (54.2) |
Case series | 125 (16.6) | 52 (41.6) |
Metanalysis | 7 (0.9) | 5 (71.4) |
Statistically Significant Results | ||
Yes | 135 (17.9) | 84 (62.2) |
No | 619 (82.1) | 299 (48.3) |
New technology or technique | ||
Yes | 278 (36.9) | 146 (52.5) |
No | 476 (63.1) | 237 (49.8) |
Principal author PhD | ||
Yes | 158 (21.0) | 91 (57.6) |
No | 596 (79.0) | 292 (49.0) |
research had a shorter median time to publication of 225 days compared to 509 days for clinical research. Industry sponsorship status was not readily apparent in the vast majority of abstracts and therefore was not collected. There was no difference in publication rate when comparing abstracts by country of origin, study design, presence of statistically significant results, mention of a new technology, technique or whether the principal author held a PhD (results not shown).
Journal | Impact Factor (2010) | n (%) |
---|---|---|
Neurosurgery | 3.30 | 66 (17.2) |
Journal of Neurosurgery | 2.74 | 65 (17.0) |
Surgical Neurology | 1.26 | 17 (4.4) |
Journal of Neurosurgery Spine | 1.59 | 16 (4.2) |
Spine | 2.51 | 15 (3.9) |
Neurosurgical Focus | 2.35 | 13 (3.4) |
Acta Neurochirurgica | 1.33 | 12 (3.1) |
Cancer Research | 8.23 | 8 (2.1) |
On multivariate binary logistic regression analysis neuro-oncology abstracts (OR 1.87; 95% CI 1.31 - 2.67; p = 0.001) and those selected for oral presentations (OR 1.97; 95% CI 1.30 - 2.99; p = 0.001) were each independent predictors of publication. Predictors of publication in journals with a higher absolute impact factor by multivariate linear regression analysis were neuro-oncology abstracts (p = 0.004), basic science research (p = 0.003) and abstracts selected for oral presentation (p = 0.036).
We set out to determine the publication rate following abstract presentation at a major neurosurgical meeting. This is important because it is one generally accepted indicator of conference quality and provides insight into the completion process for research projects. We found that 50.8% of abstracts presented at the 55th annual meeting of the CNS were published by 5.3 years of follow-up. The median time to publication was 450 days (15 months) with a wide range (646 days prior to the conference to 1943 days following the conference). Abstracts selected for oral presentation and neuro-oncology abstracts were more likely to be ultimately published. Moreover, neuro-oncology abstracts, basic science research and abstracts selected for oral presentation were published in higher impact factor journals.
Our finding of a publication rate of 50.8% following abstract presentation compares favorably to the 2-year publication rate of 44.5% determined by Scherer and colleagues in a meta-analysis including 79 studies across a wide range of subspecialties including 29720 abstracts [
Our calculated publication rate is higher than the publication rate determined in a recent report by Patel and colleagues which found a 5-year publication rate of 32.5% for CNS and AANS annual meetings across three years [
We found a pre-conference publication rate of 16%, which is high compared to other fields such as anesthesia, and general surgery where the pre-congress publication rate is less than 5% [
Our finding that abstracts selected for oral presentation were more likely to be published has been previously described in other fields [
The association between neuro-oncology abstracts and publication was less expected. Interestingly, there was no difference in the proportion of principle investigators holding a PhD in neuro-oncology versus all other subspecialty areas nor was there any statistically significant difference in publication rate for principal investigators who held a PhD versus those who did not. Finally, our analysis did not reveal an increased publication rate associated with larger sample sizes, statistically significant results, country of origin or new surgical technique or technology. It is important to note that although statistically significant results were mentioned in 17.9% of abstracts, it was difficult to reliably determine whether these results were related to primary outcome due to a distinct lack of abstract detail in many cases.
Potential limitations of our study include that our publication search underestimate the true publication rate, as there may be publications in journals that are not indexed by the three databases that we selected. Data extraction was in some cases limited by a paucity of detail. Although standardization of abstract content may mitigate this problem strict abstract length parameters (e.g. 750 words for 2011 CNS annual meeting abstracts) may accentuate it. Our publication surveillance window was 5 years which was based on previous work demonstrating that greater than 90% of articles are published within 4 years of abstract presentation [
The publication rate following abstract presentation at a major neurosurgical meeting is 50.8% with a median time to publication of 450 days. Abstracts selected for oral presentation and neuro-oncology abstracts are more likely to be published. This publication rate compares favorably with a multi-disciplinary publication rate determined by meta-analysis of 44.5% and is an endorsement for conference quality [
The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.
Author contributions to the study and manuscript preparation include the following. Conception and design: Elliott, Gourishankar, Mehta. Data acquisition: Elliott, Poon, Oliver. Analysis and interpretation of data: Elliott, Gourishankar. Manuscript preparation: Elliott. Critical revision: Gourishankar, Mehta. Study supervision: Gourishankar.
Cameron A.Elliott,VivekMehta,CandicePoon,MonikaOliver,SitaGourishankar, (2016) The Fate of Abstracts Presented at the Annual Meeting of the Congress of Neurologic Surgeons. Open Journal of Modern Neurosurgery,06,1-8. doi: 10.4236/ojmn.2016.61001