Dependability of results in conference abstracts of randomized controlled trials in ophthalmology and author financial conflicts of interest as a factor associated with full publication

Dyadic care to improve postnatal outcomes of birthing people and their infants: A scoping review protocol

INTRODUCTION

Dyadic care, which is the concurrent provision of care for a birthing person and their infant, is an approach that may improve disparities in postnatal health outcomes, but no synthesis of existing dyadic care studies has been conducted. This scoping review seeks to identify and summarize: 1) dyadic care studies globally, in which the birthing person-infant dyad are cared for together, 2) postnatal health outcomes that have been evaluated following dyadic care interventions, and 3) research and practice gaps in the implementation, dissemination, and effectiveness of dyadic care to reduce healthcare disparities.

MATERIALS AND METHODS

Eligible studies will (1) include dyadic care instances for the birthing person and infant, and 2) report clinical outcomes for at least one member of the dyad or intervention outcomes. Studies will be excluded if they pertain to routine obstetric care, do not present original data, and/or are not available in English or Spanish. We will search CINAHL, Ovid (both Embase and Medline), Scopus, Cochrane Library, PubMed, Google Scholar, Global Health, Web of Science Core Collection, gray literature, and WHO regional databases. Screening will be conducted via Covidence and data will be extracted to capture the study design, dyad characteristics, clinical outcomes, and implementation outcomes. The risk of bias will be assessed using the Joanna Briggs Institute Critical Appraisal Tool. A narrative synthesis of the study findings will be presented.

DISCUSSION

This scoping review will summarize birthing person-infant dyadic care interventions that have been studied and the evidence for their effectiveness. This aggregation of existing data can be used by healthcare systems working to improve healthcare delivery to their patients with the aim of reducing postnatal morbidity and mortality. Areas for future research will also be highlighted.

TRAIL REGISTRATION

This review has been registered at Open Science Framework (OSF, https://osf.io/5fs6e/).

TFOS Lifestyle Report: Impact of environmental conditions on the ocular surface

Environmental risk factors that have an impact on the ocular surface were reviewed and associations with age and sex, race/ethnicity, geographical area, seasonality, prevalence and possible interactions between risk factors are reviewed. Environmental factors can be (a) climate-related: temperature, humidity, wind speed, altitude, dew point, ultraviolet light, and allergen or (b) outdoor and indoor pollution: gases, particulate matter, and other sources of airborne pollutants. Temperature affects ocular surface homeostasis directly and indirectly, precipitating ocular surface diseases and/or symptoms, including trachoma. Humidity is negatively associated with dry eye disease. There is little data on wind speed and dewpoint. High altitude and ultraviolet light exposure are associated with pterygium, ocular surface degenerations and neoplastic disease. Pollution is associated with dry eye disease and conjunctivitis. Primary Sjögren syndrome is associated with exposure to chemical solvents. Living within a potential zone of active volcanic eruption is associated with eye irritation. Indoor pollution, "sick" building or house can also be associated with eye irritation. Most ocular surface conditions are multifactorial, and several environmental factors may contribute to specific diseases. A systematic review was conducted to answer the following research question: "What are the associations between outdoor environment pollution and signs or symptoms of dry eye disease in humans?" Dry eye disease is associated with air pollution (from NO2) and soil pollution (from chromium), but not from air pollution from CO or PM10. Future research should adequately account for confounders, follow up over time, and report results separately for ocular surface findings, including signs and symptoms.

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.

Publication Rate of Abstracts Presented at the North American Neuro-Ophthalmology Society Annual Meeting From 2008 to 2017

BACKGROUND

Conference abstracts serve an important role in the timely dissemination of scientific and clinical advancements, but most fail to be published. The goal of this study was to investigate the publication rate and factors associated with publication of abstracts presented at the North American Neuro-Ophthalmology Society (NANOS) Annual Meeting over a 10-year period.

METHODS

NANOS Annual Meeting abstracts from 2008 to 2017 were extracted and categorized into Walsh presentations, scientific platforms, or poster presentations. An original automated web scraping program was validated to search PubMed, Embase, Medline, and Google Scholar for publications. Publication date, journal, authors, study type, multicenter involvement, and financial disclosures were retrieved.

RESULTS

A total of 195 Walsh presentations, 231 scientific platform presentations, and 1735 scientific posters were included in the study with an overall publication rate of 31.5% (681/2,161). This was stable over the study period. Publication was the highest for scientific platforms (67.1%), followed by Walsh abstracts (36.4%) and poster presentations (27.2%). Multivariable analysis identified 3-4 authors, 5 or more authors, basic science, and sample size of 100 or more significantly correlated with subsequent publication. The top 3 countries for NANOS submissions were the United States, Canada, and South Korea, and the most frequent journal of publication was the Journal of Neuro-Ophthalmology.

CONCLUSIONS

Publication rate of NANOS abstracts is comparable to other conferences in ophthalmology and the neurological sciences. Conference attendees should be aware that more than two-thirds of abstracts fail to be published and publication rates vary widely by type of submission.

Assessment of Duplicate Publication of Chinese-Sponsored Randomized Clinical Trials

IMPORTANCE

Duplicate publications of randomized clinical trials are prevalent in the health-related literature. To date, few studies have assessed the interaction between duplicate publication and the language of the original publication.

OBJECTIVE

To assess the existence of duplicate publication and the extent to which duplicate publication is associated with the language of the original publication.

DESIGN, SETTING, AND PARTICIPANTS

In this retrospective cohort study, eligible randomized clinical trials were retrieved from trial registries, and bibliographic databases were searched to determine their publication status. Eligible randomized clinical trials were for drug interventions from January 1, 2008, to December 31, 2014. The search and analysis were conducted from March 1 to August 31, 2019. The trial registries were either primary registries recognized by the World Health Organization or the Drug Clinical Trial Registry Platform sponsored by the China Food and Drug Administration.

EXPOSURES

Individual randomized clinical trials with positive vs negative results.

MAIN OUTCOMES AND MEASURES

Journal articles were classified as main articles (determined by largest sample size and longest follow-up among all journal articles derived from that randomized clinical trial) and duplicates. The duplicates were classified into 4 types: (1) unreferenced subgroup analysis (article did not disclose itself as a subgroup analysis or reference its main article); (2) unreferenced republication (article did not disclose itself as a replicate of the main article or reference it); (3) unreferenced interim analysis (article did not disclose itself as an interim analysis or reference its main article); and (4) partial duplicate (article did not disclose its sharing a subset of participants with other articles or reference them).

RESULTS

Among 470 randomized clinical trials published by August 2019 as journal articles, 55 (11.7%) had 75 duplicates, of which 53 (70.7%) were cross-language duplicates. Of the 75 duplicates, 33 (44.0%) were unreferenced republications, 25 (33.3%) unreferenced subgroup analyses, 15 (20.0%) unreferenced interim analyses, and 2 (2.7%) partial duplicates. When the main article of a randomized clinical trial was published in Chinese, those with positive findings were 2.48 (95% CI, 1.08-5.71) times more likely to have subsequent duplicate publication than those with negative findings.

CONCLUSIONS AND RELEVANCE

In this study, most duplicates were cross-language duplicates and the most common type was unreferenced republication of the main article. Duplicate publication bias exists when the main articles of randomized clinical trials were published in Chinese, potentially misleading readers and compromising journals and evidence synthesis.

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.

Assessment of Language and Indexing Biases Among Chinese-Sponsored Randomized Clinical Trials

IMPORTANCE

Language and indexing biases may exist among Chinese-sponsored randomized clinical trials (CS-RCTs). Such biases may threaten the validity of systematic reviews.

OBJECTIVE

To evaluate the existence of language and indexing biases among CS-RCTs on drug interventions.

DESIGN, SETTING, AND PARTICIPANTS

In this retrospective cohort study, eligible CS-RCTs were retrieved from trial registries, and bibliographic databases were searched to determine their publication status. Eligible CS-RCTs were for drug interventions conducted from January 1, 2008, to December 31, 2014. The search and analysis were conducted from March 1 to August 31, 2019. Primary trial registries were recognized by the World Health Organization and the Drug Clinical Trial Registry Platform sponsored by the China Food and Drug Administration.

EXPOSURES

Individual CS-RCTs with positive vs negative results (positive vs negative CS-RCTs).

MAIN OUTCOMES AND MEASURES

For assessing language bias, the main outcome was the language of the journal in which CS-RCTs were published (English vs Chinese). For indexing bias, the main outcome was the language of the bibliographic database where the CS-RCTs were indexed (English vs Chinese).

RESULTS

The search identified 891 eligible CS-RCTs. Four hundred seventy CS-RCTs were published by August 31, 2019, of which 368 (78.3%) were published in English. Among CS-RCTs registered in the Chinese Clinical Trial Registry (ChiCTR), positive CS-RCTs were 3.92 (95% CI, 2.20-7.00) times more likely to be published in English than negative CS-RCTs; among CS-RCTs in English-language registries, positive CS-RCTs were 3.22 (95% CI, 1.34-7.78) times more likely to be published in English than negative CS-RCTs. These findings suggest the existence of language bias. Among CS-RCTs registered in ChiCTR, positive CS-RCTs were 2.89 (95% CI, 1.55-5.40) times more likely to be indexed in English bibliographic databases than negative CS-RCTs; among CS-RCTs in English-language registries, positive CS-RCTs were 2.19 (95% CI, 0.82-5.82) times more likely to be indexed in English bibliographic databases than negative CS-RCTs. These findings support the existence of indexing bias.

CONCLUSIONS AND RELEVANCE

This study suggests the existence of language and indexing biases among registered CS-RCTs on drug interventions. These biases may distort evidence synthesis toward more positive results of drug interventions.

Frequency of Abstracts Presented at Eye and Vision Conferences Being Developed Into Full-Length Publications: A Systematic Review and Meta-analysis

IMPORTANCE

Conference proceedings are platforms for early communication and dissemination of relevant and timely topics of interest. More than half of abstracts presented at biomedical conferences fail to be published in full, resulting in wasted time and resources.

OBJECTIVE

To systematically review reports evaluating the proportion of abstracts presented at eye and vision conferences that are subsequently published in full and investigate factors associated with publication.

DATA SOURCES

MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, and reference lists of included reports were systematically searched from inception to January 11, 2019.

STUDY SELECTION

Reports that examined the proportion of abstracts presented at eye and vision conferences and subsequently published in peer-reviewed journals 24 or more months later.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently assessed study eligibility, abstracted data, and evaluated the risk of bias. A meta-analysis was conducted to determine the proportion of abstracts published in full and assess factors associated with subsequent full publication.

MAIN OUTCOMES AND MEASURES

Proportion of abstracts presented at eye and vision conferences subsequently published in full.

RESULTS

There were 19 reports covering 12 261 abstracts presented at 11 unique eye and vision conferences. The overall risk of bias of the reports was low. The weighted proportion of abstracts published in full was 38.0% (95% CI, 31.7%-44.3%) and 54.9% (95% CI, 34.6%-73.7%) among reports restricted to abstracts describing randomized clinical trials. Nine reports (47.4%) investigated the proportion of abstracts subsequently published by ophthalmic subspecialties, ranging from 28.3% (oculoplastics: 95% CI, 17.2%-42.9%) to 42.7% (glaucoma: 95% CI, 34.7%-51.0%). Oral presentation (risk ratio, 1.45; 95% CI, 1.20-1.76) and basic science (risk ratio, 1.25; 95% CI, 1.05-1.47) were significantly associated with higher full publication; factors not significantly associated with full publication included positive results, randomized clinical trial vs other study design, multicenter study, and industry funding.

CONCLUSION AND RELEVANCE

More than 60% of abstracts presented at eye and vision conferences were not published in full within 2 years of conference presentation. Failure to disseminate research studies in peer-reviewed journals is not desired, especially when involving human participants.

Reliability of the Evidence Addressing Treatment of Corneal Diseases: A Summary of Systematic Reviews

Importance

Patient care should be informed by clinical practice guidelines, which in turn should be informed by evidence from reliable systematic reviews. The American Academy of Ophthalmology is updating its Preferred Practice Patterns (PPPs) for the management of the following 6 corneal diseases: bacterial keratitis, blepharitis, conjunctivitis, corneal ectasia, corneal edema and opacification, and dry eye syndrome.

Objective

To summarize the reliability of the existing systematic reviews addressing interventions for corneal diseases.

Data Source

The Cochrane Eyes and Vision US Satellite database.

Study Selection

In this study of published systematic reviews from 1997 to 2017 (median, 2014), the Cochrane Eyes and Vision US Satellite database was searched for systematic reviews evaluating interventions for the management of any corneal disease, combining eyes and vision keywords and controlled vocabulary terms with a validated search filter.

Data Extraction and Synthesis

The study classified systematic reviews as reliable when each of the following 5 criteria were met: the systematic review specified eligibility criteria for inclusion of studies, conducted a comprehensive literature search for studies, assessed risk of bias of the individual included studies, used appropriate methods for quantitative syntheses (meta-analysis) (only assessed if meta-analysis was performed), and had conclusions that were supported by the results of the systematic review. They were classified as unreliable if at least 1 criterion was not met.

Main Outcomes and Measures

The proportion of systematic reviews that were reliable and the reasons for unreliability.

Results

This study identified 98 systematic reviews that addressed interventions for 15 corneal diseases. Thirty-three of 98 systematic reviews (34%) were classified as unreliable. The most frequent reasons for unreliability were that the systematic review did not conduct a comprehensive literature search for studies (22 of 33 [67%]), did not assess risk of bias of the individual included studies (13 of 33 [39%]), and did not use appropriate methods for quantitative syntheses (meta-analysis) (12 of 17 systematic reviews that conducted a quantitative synthesis [71%]). Sixty-five of 98 systematic reviews (66%) were classified as reliable. Forty-two of the 65 reliable systematic reviews (65%) addressed corneal diseases relevant to the 2018 American Academy of Ophthalmology PPPs; 33 of these 42 systematic reviews (79%) are cited in the 2018 PPPs.

Conclusions and Relevance

One in 3 systematic reviews addressing interventions for corneal diseases are unreliable and thus were not used to inform PPP recommendations. Careful adherence by systematic reviewers and journal editors to well-established best practices regarding systematic review conduct and reporting might help make future systematic reviews in eyes and vision more reliable.

Legal regulations, ethical guidelines and recent policies to increase transparency of clinical trials

Timely and accurate dissemination of outcomes is essential to accomplish main benefits of scientific research including clinical trials. Clinical trial results can be disseminated in two main ways: by publication in a peer-reviewed journal and by posting on a publicly available clinical trial register. The credibility of the literature on clinical trials is significantly diminished because a high percentage of trials is not published. While current legal regulations both in the European Union (EU) and the USA impose a duty to submit summary results of clinical trials to a respective register (EU Clinical Trial Register and ClinicalTrials.gov, respectively), the compliance with this requirement has been generally inadequate. Trial outcomes can be also made accessible by data sharing. However, in spite of the wide promotion of this idea, the access of investigators to participant-level datasets remains limited. The main objective of this review is to discuss current legal regulations, international standards, ethical guidelines and recent policies pertaining to dissemination of clinical trial results.

Searching practices and inclusion of unpublished studies in systematic reviews of diagnostic accuracy

Introduction

Many diagnostic accuracy studies are never reported in full in a peer‐reviewed journal. Searching for unpublished studies may avoid bias due to selective publication, enrich the power of systematic reviews, and thereby help to reduce research waste. We assessed searching practices among recent systematic reviews of diagnostic accuracy.

Methods

We extracted data from 100 non‐Cochrane systematic reviews of diagnostic accuracy indexed in MEDLINE and published between October 2017 and January 2018 and from all 100 Cochrane systematic reviews of diagnostic accuracy published by December 2018, irrespective of whether meta‐analysis had been performed.

Results

Non‐Cochrane and Cochrane reviews searched a median of 4 (IQR 3‐5) and 6 (IQR 5‐9) databases, respectively; most often MEDLINE/PubMed (n = 100 and n = 100) and EMBASE (n = 81 and n = 100). Additional efforts to identify studies beyond searching bibliographic databases were performed in 76 and 98 reviews, most often through screening reference lists (n = 71 and n = 96), review/guideline articles (n = 18 and n = 52), or citing articles (n = 3 and n = 42). Specific sources of unpublished studies were searched in 22 and 68 reviews, for example, conference proceedings (n = 4 and n = 18), databases only containing conference abstracts (n = 2 and n = 33), or trial registries (n = 12 and n = 39). At least one unpublished study was included in 17 and 23 reviews. Overall, 39 of 2082 studies (1.9%) included in non‐Cochrane reviews were unpublished, and 64 of 2780 studies (2.3%) in Cochrane reviews, most often conference abstracts (97/103).

Conclusion

Searching practices vary considerably across systematic reviews of diagnostic accuracy. Unpublished studies are a minimal fraction of the evidence included in recent reviews.

How should systematic reviewers handle conference abstracts? A view from the trenches

BACKGROUND

While identifying and cataloging unpublished studies from conference proceedings is generally recognized as a good practice during systematic reviews, controversy remains whether to include study results that are reported in conference abstracts. Existing guidelines provide conflicting recommendations.

MAIN BODY

The main argument for including conference abstracts in systematic reviews is that abstracts with positive results are preferentially published, and published sooner, as full-length articles compared with other abstracts. Arguments against including conference abstracts are that (1) searching for abstracts is resource-intensive, (2) abstracts may not contain adequate information, and (3) the information in abstracts may not be dependable. However, studies comparing conference abstracts and fully published articles of the same study find only minor differences, usually with conference abstracts presenting preliminary results. Other studies that have examined differences in treatment estimates of meta-analyses with and without conference abstracts report changes in precision, but usually not in the treatment effect estimate. However, in some cases, including conference abstracts has made a difference in the estimate of the treatment effect, not just its precision. Instead of arbitrarily deciding to include or exclude conference abstracts in systematic reviews, we suggest that systematic reviewers should consider the availability of evidence informing the review. If available evidence is sparse or conflicting, it may be worthwhile to search for conference abstracts. Further, attempts to contact authors of abstracts or search for protocols or trial registers to supplement the information presented in conference abstracts is prudent. If unique information from conference abstracts is included in a meta-analysis, a sensitivity analysis with and without the unique results should be conducted.

CONCLUSIONS

Under given circumstances, it is worthwhile to search for and include results from conference abstracts in systematic reviews.

Conference abstracts describing systematic reviews on pain were selectively published, not reliable, and poorly reported

OBJECTIVE

The objective of the study was to determine the reporting quality of systematic review (SR) abstracts presented at World Congresses on Pain (WCPs) and to quantify agreement in results presented in those abstracts with their corresponding full-length publications.

STUDY DESIGN AND SETTING

We screened abstracts of five WCPs held from 2008 to 2016 to find abstracts describing SRs. Two authors searched for corresponding full publications using PubMed and Google Scholar in April 2018. Methods and outcomes extracted from abstracts were compared with their corresponding full publications. The reporting quality of abstracts was evaluated against the PRISMA for Abstracts (PRISMA-A) checklist.

RESULTS

We identified 143 conference abstracts describing SRs. Of these, 90 (63%) were published as full-length articles in peer-reviewed journals by April 2018, with a median time from conference presentation to publication of 5 months (interquartile range: -0.25 to 14 months). Among 79 abstract-publication pairs evaluable for discordance, there was some form of discordance in 40% of pairs. Qualitative discordance (different direction of the effect) was found in 13 analyzed pairs (16%). The median adherence by abstracts to each PRISMA-A checklist item was 33% (interquartile range: 29% to 42%).

CONCLUSION

Conference abstracts of pain SRs are selectively published, not reliable, and poorly reported.

Data extraction methods: an analysis of internal reporting discrepancies in single manuscripts and practical advice

BACKGROUND

Data extraction from reports about experimental or observational studies is a crucial methodological step informing evidence syntheses, such as systematic reviews (SRs) and overviews of SRs. Reporting discrepancies were defined as pairs of statements that could not both be true. Authors of SRs and overviews of SRs can encounter reporting discrepancies among multiple sources when extracting data-a manuscript and a conference abstract, and a manuscript and a clinical trial registry. However, these discrepancies can also be found within a single manuscript published in a scientific journal.

OBJECTIVES

Hereby, we describe examples of internal reporting discrepancies that can be found in a single source, with the aim of raising awareness among authors of SRs and overviews of SRs about such potential methodological issues.

CONCLUSIONS

Authors of SRs and overviews of SRs should check whether the same information is reported in multiple places within a study and compare that information. Independent data extraction by two reviewers increases the chance of finding discrepancies, if they exist. We provide advice on how to deal with different types of discordances and how to report such discordances when conducting SRs and overviews of SRs.

Publication bias may exist among prognostic accuracy studies of middle cerebral artery Doppler ultrasound

OBJECTIVES

The objective of this study was to assess if there is evidence of publication bias in prognostic accuracy studies of middle cerebral artery (MCA) or cerebroplacental ratio (CPR) for adverse perinatal outcome.

STUDY DESIGN AND SETTING

We queried PubMed, EMBASE, the Cochrane Library, and ClinicalTrials.gov and searched abstract books of five perinatal conferences (1989-2017). We included prognostic accuracy studies on MCA and/or CPR. Highest reported accuracy estimates, sample size, study design, and conclusion positivity were extracted and compared.

RESULTS

We included 127 full-text articles and 51 conference abstracts, 29 of which had not been reported as full-text article. In conference abstracts not reported in full, median negative predictive value was significantly lower compared to full-text articles (0.79 [interquartile range 0.67-0.97] vs. 0.95 [0.89-0.99]; P < 0.001). No significant difference was identified for positive predictive value (0.62 vs. 0.59; P = 0.827), sensitivity (0.67 vs. 0.71; P = 0.159), and specificity (0.86 vs. 0.86; P = 0.632). Study design differed significantly as well (P = 0.030), with fewer prospective studies in conference abstracts not reported in full compared to full-text articles (28% vs. 54%). We found no significant differences in sample size or conclusion positivity.

CONCLUSION

Possibly, a publication bias in previously published meta-analyses of MCA and CPR has led to overly generous estimates of prognostic performance.

The fate of abstracts presented at international ophthalmology meetings: 2- and 5-year publication rates

PURPOSE

To investigate the 2- and 5-year publication rates of abstracts presented at major international ophthalmology meetings.

METHODS

We analyzed a random selection of 20% of free papers and posters presented at the 2010 meeting of the Association for Research in Vision and Ophthalmology, the American Academy of Ophthalmology, the European Association for Vision and Eye Research, the Asia-Pacific Academy of Ophthalmology, and the 2009 European Society of Ophthalmology meeting. The PubMed (MEDLINE) database was searched to identify matching journal articles. Data collection included: topic, geographic origin, presentation type, publication status, and impact factor. A multivariate logistic regression model was used to assess odds of publication and impact factor.

RESULTS

Our analysis included 1742 research abstracts. The overall 2- and 5-year publication rates were 33.3% (n = 579) and 47.2% (n = 823), respectively. The highest publication rates were found for Association for Research in Vision and Ophthalmology (36.1% and 51.9%, p < 0.0001), paper presentations (44.5% and 60.5%, p < 0.0001), researches from Oceania (35.8% and 57.1%, p < 0.05) and North America (36.2% and 50.5%, p < 0.05), and Basic science studies (44% and 60.3%, p < 0.01). After adjustments, higher odds of publication were shown by the Association for Research in Vision and Ophthalmology and the American Academy of Ophthalmology meetings (p < 0.0001), papers (p < 0.0001), and Basic science (p < 0.05). The median impact factor was 3.20 (interquartile range = 1.90-3.40).

CONCLUSION

Less than half of abstracts presented at the major ophthalmology meetings reach publication within 5 years of their initial presentation. Professionals attending meetings may consider adopting a more critical approach to the preliminary results reported in presented abstracts. Increasing publication rates and reducing potential publication bias is of interest.

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.

Publication Fate of Abstracts Presented at Four British Surgical Meetings: An 11-Year Follow-Up

BACKGROUND

The gold standard for research is publication within a peer-reviewed journal. There is a discrepancy between the number of abstracts presented at scientific meetings and the number published as full articles. We identified publication rates for the 2012 meetings of four British surgical societies. These were the Association of Surgeons of Great Britain & Ireland (ASGBI), the Vascular Society of Great Britain and Ireland, the British Transplantation Society (BTS), and the Association of Coloproctology of Great Britain and Ireland (ACPGBI). We also compared publication rates with these societies' 2001 meetings and identified univariate factors associated with publication.

MATERIALS AND METHODS

PubMed was searched to identify publications stemming from meeting abstracts. We extracted abstract characteristics to identify factors associated with publication and also characteristics of subsequent publications to enable comparison.

RESULTS

Publication rates were 24.1% (ASGBI), 24.6% (BTS), 21.7% (ACPGBI), and 39.4% (Vascular Society of Great Britain and Ireland). Rates for ASGBI, BTS, and ACPGBI meetings were significantly lower compared to 2001 meetings (P = 0.001-0.026). Mean time to publication was 12.1-22.0 mo. Mean 5-y impact factor differed significantly between meetings (P = 0.001), with the BTS meeting having the highest mean 5-y impact factor (4.658). Factors associated with publication included being an oral presentation (ASGBI P = 0.001), multi-institution study (ASGBI P = 0.003), or randomized-controlled trial (BTS P = 0.049).

CONCLUSIONS

Reduced publication rates may represent increased acceptance of low-quality abstracts at meetings or a more competitive journal submission process. Further data are required to strengthen conclusions. Nonetheless, authors and meeting organizers should push for higher quality abstracts to promote future peer-reviewed journal publication.

Identification and description of controlled clinical trials published in Spanish Ophthalmology Journals

PURPOSE

Properly conducted controlled clinical trials (CCTs) provide the highest level of evidence for optimising decision-making in healthcare. Electronic search strategies do not exhaustively retrieve them, because of issues related to indexing, exclusion of journals in languages other than English, among others. A handsearch approach is therefore warranted. We aimed to identify all CCTs published in Ophthalmology journals in Spain, to describe their main features, and to submit them to the Cochrane Register of CCTs (CENTRAL).

METHODS

After identifying all Spanish Ophthalmology Journals, we conducted a systematic handsearch following Cochrane guidelines. When appropriate, results were compared against electronic searches. A descriptive analysis was completed, including risk of bias assessment.

RESULTS

We identified 18 eligible journals; 10 074 original articles, editorials, letters to the editor, abstracts and conference proceedings were assessed via handsearching for inclusion. Of these, 136 were subject to title and abstract screening, after which 102 were classified as CCTs. We identified three articles via electronic searches that had not been detected via handsearch, for a total of 105 CCTs. Among these, the most investigated pathologies were cataracts (32/105; 30.5%) and glaucoma (23/105 21.9%). Regarding risk of bias, 104/105 (99.0%) were deemed as "high risk of bias", mainly due to flaws in sequence generation and allocation concealment. 15/105 (14.3%) mentioned conflicts of interest, half of which had something to declare. No CCT reported adherence to CONSORT.

CONCLUSION

Spanish Ophthalmology journals publish a low number of CCTs, with limited methodological quality. Handsearching was more sensitive than the electronic searching. Abbreviations CCT: Controlled clinical trial.

Opinions and potential solutions regarding dissemination bias from funding agencies of biomedical research in Europe

RATIONALE, AIMS, AND OBJECTIVES

Several studies have found that about half of research results from clinical trials are never published. Until now, there has been little information on the views that funding agencies of biomedical research in Europe have regarding this issue and its possible solutions.

METHODS

An electronic survey was conducted among funding agencies from 34 European countries. Participants were asked about their opinions, policies, and potential solutions regarding dissemination bias. On the basis of the results of this survey and the input of the OPEN Consortium and of representatives of stakeholder groups in the knowledge generation process, we formulated recommendations for funding agencies to reduce dissemination bias.

RESULTS

We received responses from 64 funding agencies of biomedical medicine from most European countries, out of 245 that were contacted (26%). Of these, 56 funded research at the national and/or international level and were therefore eligible to participate. Policies encouraging publication increased over time: 33 (58.9%) of agencies enforced them in 2005 compared to 38 (67.6%) in 2012. However, only 13 (23.2%) had knowledge of the publications related to research funded in 2005, 23 (41.1%) were able to provide only an estimate, and 20 (35.7%) did not know at all. Regarding recommendations to control dissemination bias, we propose that funding agencies request the dissemination of research results irrespective of the direction of findings. We also call for measures that allow evaluating funded projects past the contractual period and until dissemination of results. Funding agencies should create publicly accessible databases with information on funded projects and dissemination efforts.

CONCLUSION

Despite having policies to encourage publication of results, most funding agencies fail to implement such measures or to ensure compliance. We propose recommendations that could be incorporated in the blueprint of calls for proposals and contracts agreed upon by funding agencies and grant recipients.

Publication outcome of abstracts submitted to the American Academy of Ophthalmology meeting

Objective

Abstracts submitted to meetings are subject to less rigorous peer review than full-text manuscripts. This study aimed to explore the publication outcome of abstracts presented at the American Academy of Ophthalmology (AAO) annual meeting.

Methods

Abstracts presented at the 2008 AAO meeting were analyzed. Each presented abstract was sought via PubMed to identify if it had been published as a full-text manuscript. The publication outcome, journal impact factor (IF), and time to publication were recorded.

Results

A total of 690 abstracts were reviewed, of which 39.1% were subsequently published. They were published in journals with a median IF of 2.9 (range 0–7.2) and a median publication time of 426 days (range 0–2,133 days). A quarter were published in the journal Ophthalmology, with a shorter time to publication (median 282 vs. 534 days, p=0.003). Oral presentations were more likely to be published than poster presentations (57.8% vs. 35.9%, p<0.001) and in journals with higher IFs (3.2 vs. 2.8, p=0.02). Abstracts describing rare diseases had higher publication rates (49.4% vs. 38.0%, p=0.04) and were published in higher IF journals (3.7 vs. 2.9, p=0.03), within a shorter period of time (358 vs. 428 days, p=0.03). In multivariate analysis, affiliation with an institute located in the United States (p=0.002), abstracts describing rare diseases (p=0.03), and funded studies (p=0.03) were associated with publication in higher IF journals.

Conclusions

Almost 40% of abstracts were published. Factors that correlated with publication in journals with higher IF were a focus on rare diseases, affiliation with a US institute, and funding.

Practical guidance for using multiple data sources in systematic reviews and meta-analyses (with examples from the MUDS study)

Data for individual trials included in systematic reviews may be available in multiple sources. For example, a single trial might be reported in 2 journal articles and 3 conference abstracts. Because of differences across sources, source selection can influence the results of systematic reviews. We used our experience in the Multiple Data Sources in Systematic Reviews (MUDS) study, and evidence from previous studies, to develop practical guidance for using multiple data sources in systematic reviews. We recommend the following: (1) Specify which sources you will use. Before beginning a systematic review, consider which sources are likely to contain the most useful data. Try to identify all relevant reports and to extract information from the most reliable sources. (2) Link individual trials with multiple sources. Write to authors to determine which sources are likely related to the same trials. Use a modified Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) flowchart to document both the selection of trials and the selection of sources. (3) Follow a prespecified protocol for extracting trial characteristics from multiple sources. Identify differences among sources, and contact study authors to resolve differences if possible. (4) Prespecify outcomes and results to examine in the review and meta-analysis. In your protocol, describe how you will handle multiple outcomes within each domain of interest. Look for outcomes using all eligible sources. (5) Identify which data sources were included in the review. Consider whether the results might have been influenced by data sources used. (6) To reduce bias, and to reduce research waste, share the data used in your review.

Search for unpublished data by systematic reviewers: an audit

OBJECTIVES

We audited a selection of systematic reviews published in 2013 and reported on the proportion of reviews that researched for unpublished data, included unpublished data in analysis and assessed for publication bias.

DESIGN

Audit of systematic reviews.

DATA SOURCES

We searched PubMed and Ovid MEDLINE In-Process & Other Non-Indexed Citations between 1 January 2013 and 31 December 2013 for the following journals: Journal of the American Medical Association, The British Medical Journal, Lancet, Annals of Internal Medicine and the Cochrane Database of Systematic Reviews. We also searched the Cochrane Library and included 100 randomly selected Cochrane reviews.

ELIGIBILITY CRITERIA

Systematic reviews published in 2013 in the selected journals were included. Methodological reviews were excluded.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently reviewed each included systematic review. The following data were extracted: whether the review searched for grey literature or unpublished data, the sources searched, whether unpublished data were included in analysis, whether publication bias was assessed and whether there was evidence of publication bias.

MAIN FINDINGS

203 reviews were included for analysis. 36% (73/203) of studies did not describe any attempt to obtain unpublished studies or to search grey literature. 89% (116/130) of studies that sought unpublished data found them. 33% (68/203) of studies included an assessment of publication bias, and 40% (27/68) of these found evidence of publication bias.

CONCLUSION

A significant fraction of systematic reviews included in our study did not search for unpublished data. Publication bias may be present in almost half the published systematic reviews that assessed for it. Exclusion of unpublished data may lead to biased estimates of efficacy or safety in systematic reviews.

Searching ClinicalTrials.gov did not change the conclusions of a systematic review

OBJECTIVES

We assessed the effect of searching ClinicalTrials.gov on the conclusions of a systematic review.

STUDY DESIGN AND SETTING

We conducted this case study concurrently with a systematic review. We searched ClinicalTrials.gov on March 9, 2016, to identify trial records eligible for inclusion in the review. Two independent reviewers screened ClinicalTrials.gov records. We compared conclusions and strength of evidence grade with and without ClinicalTrials.gov records for 31 comparisons and 2 outcomes.

RESULTS

We identified 106 trials (53 in the peer-reviewed literature only, 23 in ClinicalTrials.gov only, and 30 in both sources). For one comparison, the addition of results identified through ClinicalTrials.gov reduced the pooled effect size. We found evidence of selective outcome reporting for two comparisons and suspected publication bias for another two comparisons. For all other comparisons, searching ClinicalTrials.gov did not change conclusions or the strength of evidence grading for the two outcomes.

CONCLUSION

Our search of ClinicalTrials.gov bolstered suspicions of reporting biases but did not change either the conclusions or the strength of evidence grading. Further research is needed to determine the effect of searching ClinicalTrials.gov on the conclusions of systematic reviews in different topic areas and as the new rules for registration of trial results take effect.

Clinical trials and systematic reviews addressing similar interventions for the same condition do not consider similar outcomes to be important: a case study in HIV/AIDS

BACKGROUND

The usefulness of clinical trials and systematic reviews is compromised when they report different outcomes. We compared outcomes in reviews of HIV/AIDS and the trials included in the reviews.

STUDY DESIGN AND SETTING

We examined all Cochrane reviews of HIV/AIDS (as of June 2013) that included ≥1 trial and the trials that the reviews included. We compared outcomes within subgroups defined by type of intervention: clinical management, biomedical prevention, behavioral prevention, and health services.

RESULTS

We included 84 reviews that encompassed 524 trials. Although the median number of outcomes per trial (8) and per review (7.5) was similar, the trials reported a considerably greater number of unique outcomes than the reviews (779 vs. 218), ranging from 2.3 times greater (clinical management) to 5.4 times greater (behavioral prevention). High proportions of trial outcomes were not in any review: 68% (clinical management) to 83% (behavioral prevention). Lower proportions of review outcomes were not in any trial: 11% (clinical management) to 39% (health services).

CONCLUSION

Outcomes in trials and reviews are not well aligned for appropriate inclusion of trial results in reviews and meta-analyses. Differences in perspectives, goals, and constraints between trialists and reviewers may explain differences in outcomes they consider important.

Reported estimates of diagnostic accuracy in ophthalmology conference abstracts were not associated with full-text publication

OBJECTIVE

To assess whether conference abstracts that report higher estimates of diagnostic accuracy are more likely to reach full-text publication in a peer-reviewed journal.

STUDY DESIGN AND SETTING

We identified abstracts describing diagnostic accuracy studies, presented between 2007 and 2010 at the Association for Research in Vision and Ophthalmology (ARVO) Annual Meeting. We extracted reported estimates of sensitivity, specificity, area under the receiver operating characteristic curve (AUC), and diagnostic odds ratio (DOR). Between May and July 2015, we searched MEDLINE and EMBASE to identify corresponding full-text publications; if needed, we contacted abstract authors. Cox regression was performed to estimate associations with full-text publication, where sensitivity, specificity, and AUC were logit transformed, and DOR was log transformed.

RESULTS

A full-text publication was found for 226/399 (57%) included abstracts. There was no association between reported estimates of sensitivity and full-text publication (hazard ratio [HR] 1.09 [95% confidence interval {CI} 0.98, 1.22]). The same applied to specificity (HR 1.00 [95% CI 0.88, 1.14]), AUC (HR 0.91 [95% CI 0.75, 1.09]), and DOR (HR 1.01 [95% CI 0.94, 1.09]).

CONCLUSION

Almost half of the ARVO conference abstracts describing diagnostic accuracy studies did not reach full-text publication. Studies in abstracts that mentioned higher accuracy estimates were not more likely to be reported in a full-text publication.