Reporting quality of randomized controlled trial abstracts published in leading laser medicine journals: an assessment using the CONSORT for abstracts guidelines

THE REPORTING QUALITY OF SYSTEMATIC REVIEW ABSTRACTS IN LEADING GENERAL DENTAL JOURNALS: A METHODOLOGICAL STUDY

OBJECTIVE

To assess the reporting quality of systematic review (SR) abstracts published in leading general dental journals according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Abstracts (PRISMA-A) guidelines, and to identify factors associated with overall reporting quality.

METHODS

We identified SR abstracts published in 10 leading general dental journals and assessed their reporting quality. For each abstract, an overall reporting score (ORS, range: 0-13) was calculated. Risk ratio (RR) was calculated to compare the reporting quality of abstracts in Pre-PRISMA (2011-2012) and Post-PRISMA (2017-2018) periods. Univariable and multivariable linear regression analyses were performed to identify factors associated with reporting quality.

RESULTS

A total of 104 eligible abstracts were included. The mean ORS was 5.59 (SD = 1.48) and 6.97 (1.74) respectively in the Pre- and Post-PRISMA abstracts, with statistically significant difference (mean difference = 1.38; 95% CI: 0.70, 2.05). Reporting of the exact P-value (B = 1.22; 95% CI: 0.45, 1.99) was a significant predictor of higher reporting quality.

CONCLUSION

The reporting quality of SR abstracts published in leading general dental journals improved after the release of PRISMA-A guidelines, but is still suboptimal. Relevant stakeholders need to work together to enhance the reporting quality of SR abstracts in dentistry.

Abstracts of randomized controlled trials in the field of dentofacial trauma: Reporting quality and spin

BACKGROUND/AIM

Abstracts of randomized controlled trials (RCTs) provide a summary of the entire trial report. Their transparent, detailed, and accurate reporting is essential for clinical decision-making and evidence-based dental practice. The aim of this study was to assess the reporting quality and prevalence of spin in abstracts of RCTs in the field of dentofacial trauma.

MATERIALS AND METHODS

The PubMed database was searched to identify RCT reports published between 2017 and 2021 in the field of dentofacial trauma. The reporting quality of abstracts was assessed according to the 16-item CONSORT for Abstracts checklist and measured with an overall quality score (OQS, range: 0-16). Linear regression analyses were used to identify factors associated with reporting quality. Among the included RCTs, parallel-group RCTs with non-significant primary outcomes were selected for spin assessment using predefined spin strategies.

RESULTS

One hundred and twelve eligible abstracts were identified and included. The mean OQS was 4.51 (SD, 1.35; 95% CI, 4.26-4.76). Abstracts with more than 250 words (p = .004) and a structured format (p = .032) had significantly better reporting quality. Of the 30 abstracts that were eligible for spin assessment, spin was identified in 23 (76.7%). Among these, spin was observed in the Conclusions sections of 22 abstracts (73.3%) and the Results sections of 9 abstracts (30.0%).

CONCLUSIONS

Among RCT abstracts in the field of dentofacial trauma, the reporting quality was sub-optimal and the prevalence of spin was relatively high. Strict adherence to the CONSORT for Abstracts guidelines is needed to ensure complete and transparent reporting. Relevant stakeholders need to make concerted efforts to avoid spin.

Reporting quality for abstracts of randomised trials on child and adolescent depression prevention: a meta-epidemiological study on adherence to CONSORT for abstracts

OBJECTIVES

This study aimed to investigate adherence to Consolidated Standards of Reporting Trials (CONSORT) for abstracts in reports of randomised trials on child and adolescent depression prevention. Secondary objective was to examine factors associated with overall reporting quality.

DESIGN

Meta-epidemiological study.

DATA SOURCES

We searched MEDLINE, EMBASE, PsycINFO, PsycArticles and CENTRAL.

ELIGIBILITY CRITERIA

Trials were eligible if the sample consisted of children and adolescents under 18 years with or without an increased risk for depression or subthreshold depression. We included reports published from 1 January 2003 to 8 August 2020 on randomised controlled trials (RCTs) and cluster randomised trials (CRTs) assessing universal, selective and indicated interventions aiming to prevent the onset of depression or reducing depressive symptoms.

DATA EXTRACTION AND SYNTHESIS

As the primary outcome measure, we assessed for each trial abstract whether information recommended by CONSORT was adequately reported, inadequately reported or not reported. Moreover, we calculated a summative score of overall reporting quality and analysed associations with trial and journal characteristics.

RESULTS

We identified 169 eligible studies, 103 (61%) RCTs and 66 (39%) CRTs. Adequate reporting varied considerably across CONSORT items: while 9 out of 10 abstracts adequately reported the study objective, no abstract adequately provided information on blinding. Important adverse events or side effects were only adequately reported in one out of 169 abstracts. Summative scores for the abstracts' overall reporting quality ranged from 17% to 83%, with a median of 40%. Scores were associated with the number of authors, abstract word count, journal impact factor, year of publication and abstract structure.

CONCLUSIONS

Reporting quality for abstracts of trials on child and adolescent depression prevention is suboptimal. To help health professionals make informed judgements, efforts for improving adherence to reporting guidelines for abstracts are needed.

Reporting Quality in Abstracts of Randomized Controlled Trials Published in High-Impact Occupational Therapy Journals

IMPORTANCE

Adequate reporting in the abstracts of randomized controlled trials (RCTs) is essential to enable occupational therapy practitioners to critically appraise the validity of findings.

OBJECTIVE

To evaluate the reporting quality and characteristics of RCT abstracts published between 2008 and 2018 in the occupational therapy journals with the five highest impact factors in 2018.

DESIGN

A descriptive cross-sectional study.

DATA SOURCES

The American Journal of Occupational Therapy (AJOT), Australian Occupational Therapy Journal (AOTJ), Canadian Journal of Occupational Therapy (CJOT), Scandinavian Journal of Occupational Therapy (SJOT), and Physical and Occupational Therapy in Pediatrics (POTP) were identified using a Web of Science search.

STUDY SELECTION AND DATA COLLECTION

We searched Scopus for abstracts in the five included journals. We used a 17-point scale based on the CONSORT for Abstracts (CONSORT-A) checklist to assess reporting quality. We also identified characteristics of the abstracts.

FINDINGS

Seventy-eight RCT abstracts were assessed and showed moderate to low adherence to the CONSORT-A checklist (Mdn = 8, interquartile range = 7-9). Abstracts of articles with authors from a higher number of institutions, European first authors, and >200 words had higher CONSORT-A scores. The most underreported CONSORT-A items were trial design, blinding, numbers analyzed, outcome (results), harms, trial registration, and funding.

CONCLUSIONS AND RELEVANCE

Between 2008 and 2018, the reporting quality in RCT abstracts from the five highest impact occupational therapy journals was moderate to low. Inadequate reporting in RCT abstracts raises the risk that occupational therapy practitioners will make ineffective clinical decisions based on misinterpretation of findings. What This Article Adds: Reporting quality in RCT abstracts in occupational therapy journals is moderate to low. Journal editors should require authors of RCTs to use the CONSORT-A checklist to promote optimal reporting and transparency in abstracts.

Avoiding searching for outcomes called for additional search strategies: A study of Cochrane review searches

OBJECTIVE

A search strategy for a systematic review that use the PICO-model as framework, should include the population, the intervention(s), and the type(s) of study design. According to existing guidelines outcome should generally be excluded from the search strategy unless the search is multistranded. However, a recent study found that approximately 10% (51) of recent Cochrane reviews on interventions included outcomes in their literature search strategies. This study aims to analyze the alternatives to including outcome in a search strategy, by analyzing these recent Cochrane reviews.

STUDY DESIGN

This study analyses the 51 Cochrane reviews that included outcomes in their literature search strategies and analyzes the results of alternative search strategies that follow current recommendations.

RESULTS

Despite a small study sample of 51 reviews, the results show that many of the reviews excluded some of the recommended elements due to very broadly defined elements (e.g., all interventions or all people). Furthermore, excluding outcome from the search strategy is followed by an enormous increase in the number of retrieved records making it unmanageable to screen, if using a single stranded search strategy.

CONCLUSION

Recommendations for search strategies in difficult cases are called for.

Reporting quality of abstracts of randomized controlled trials related to implant dentistry

BACKGROUND

Abstracts of scientific articles should be accurate and detailed in summarizing the information in the full-text because they are the first article section the reader examines. This study assessed the reporting quality of randomized controlled trials (RCTs) abstracts related to implant dentistry and examined associations between reporting quality and study characteristics.

METHODS

On the 17th of January 2021, we searched the PubMed database for abstracts of RCTs published in high-ranked periodontology and implant dentistry journals from 2016 to 2021. For each abstract, we assessed if the Consolidated Standards of Reporting Trials for abstracts (CONSORT-A) checklist items were reported completely, partially, or not reported. An Overall CONSORT Score (OCS) and relative score (OCS%) were calculated as a proxy to checklist adherance. Linear regression models were fitted to analyze associations between trial characteristics and completeness of reporting.

RESULTS

Four-hundred and thirty four of the 678 retrieved abstracts were eligible for inclusion. The mean OCS and OCS% were 6,23 (standard deviation [SD] = 1.56) or 41.5% (SD = 10.4), respectively. Items most frequently reported included the title (n = 434; 100%), intended intervention (n = 425; 98%) and conclusions (n = 430; 99%). Participant allocation, blinding, and trial registration were rarely completely reported with frequencies of 2%, 3% and 4%, respectively. We found that number of authors, continent, type of RCT, number of centers, report of ethical approval, funding, structure and length of the abstract were associated with better abstract reporting.

CONCLUSION

The reporting quality of abstracts in RCTs related to implant dentistry is suboptimal. Journals should start to incorporate and endorse the use of the CONSORT-A guidelines in their instructions to authors to enhance reporting quality. This article is protected by copyright. All rights reserved.

Evaluation of Spin in the Abstracts of Systematic Reviews and Meta-Analyses of Atopic Dermatitis Treatments and Interventions

BACKGROUND

Spin - the misrepresentation of a study's results - has been identified in abstracts of studies focused on a variety of disorders from multiple fields of medicine.

OBJECTIVES

This study's primary objective was to evaluate the abstracts of systematic reviews and meta-analyses focused on the treatment of atopic dermatitis for the nine most severe forms of spin.

METHODS

We systematically searched Embase and MEDLINE for systematic reviews of atopic dermatitis therapies. Screening and data extraction occurred in a masked, duplicate fashion. Each included study was evaluated for the nine most severe types of spin and other study characteristics.

RESULTS

Our searches retrieved 2,456 studies, of which 113 were included for data extraction. Spin was found in 74.3% of our included studies (84/113). Spin type 6 occurred most frequently (68/113, 60.2%). Spin types 1, 2, and 9 were not identified. All industry-funded systematic reviews contained spin in their abstract. The presence of spin was not associated with any specific study characteristics, including the methodological quality of the study.

CONCLUSIONS

Severe forms of spin were found in the majority of abstracts for systematic reviews of atopic dermatitis treatments. Steps should be taken to prevent spin to improve the quality of reporting in abstracts.

Do not make clinical decisions based on abstracts of healthcare research: A systematic review

OBJECTIVE

To summarize the reporting quality of healthcare abstracts and inconsistencies between abstracts and full texts.

STUDY DESIGN AND SETTING

This systematic review included overviews of randomized controlled trials (RCTs) and systematic reviews (SRs) that summarized data of healthcare abstracts on reporting of abstracts and consistency of abstracts with the full text. Searches were performed in PubMed, CENTRAL, Cochrane Library and EMBASE databases from 1900 to February 2019. Two authors screened the overviews and extracted the data. All analyses were descriptive and divided into two main groups: abstracts' reporting quality and abstracts' consistency with the full text. Abstracts were considered poorly reported and inconsistent with the full text if more than 5% of abstracts' information was not fully reported or not consistent with the full text.

RESULTS

27 overviews analyzing 5,194 RCTs and 866 SRs were retrieved for reporting quality of abstracts. A total of 22 overviews analyzing 2,025 RCTs and 551 SRs were included for consistency of abstracts with the full text. Abstracts across all healthcare areas presented poor reporting quality and were inconsistent with the full texts, with results and conclusions as the most inconsistent sections.

CONCLUSION

Abstracts of healthcare RCTs and SRs have shown a large room for improvement in reporting quality and consistency with the full text. Authors, journal editors and reviewers need to give the highest priority to this matter.

Reporting quality of systematic review abstracts in operative dentistry: An assessment using the PRISMA for Abstracts guidelines

OBJECTIVES

To assess and compare the reporting quality of systematic review (SR) abstracts in operative dentistry published before and after the release of Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Abstracts (PRISMA-A), and to identify factors associated with reporting quality.

METHODS

PubMed was searched for abstracts published during 2010-2012 (Pre-PRISMA period) and 2017-2019 (Post-PRISMA period). Reporting quality was assessed and scored using a modified 13-item PRSIMA-A checklist. Risk ratio (RR) was used to compare the adequate reporting rate of each item between the two periods. Univariable and multivariable linear regression analyses were performed to identify factors associated with reporting quality.

RESULTS

A total of 160 abstracts were included and assessed. Only four items ('objective', 'results of main outcomes', 'description of the effect' and 'interpretation') were adequately reported in most abstracts (>75 %). According to the multivariable analysis, greater word count (P = 0.001), being published in the Post-PRISMA period (P = 0.025) and geographic origin from Asia (P = 0.025) or South America (P = 0.015) were significantly associated with higher reporting quality.

CONCLUSIONS/CLINICAL SIGNIFICANCE

The reporting quality of SR abstracts in operative dentistry had improved significantly after the publication of PRISMA-A, but was still suboptimal. Researchers, reviewers and journal editors in operative dentistry need to be familiar with the PRISMA-A checklist, and make concerted efforts to improve the reporting of SR abstracts.

Quality assessment of randomized controlled trial abstracts on drug therapy of periodontal disease from the abstracts published in dental Science Citation Indexed journals in the last ten years

Background

Randomized controlled trials (RCTs) provide the highest level of evidence and are likely to influence clinical decision-making. This study evaluated the reporting quality of RCT abstracts on drug therapy of periodontal disease and assessed the associated factors.

Material and Methods

The Pubmed database was searched for periodontal RCTs published in Science Citation Indexed (SCI) dental journals from 2010/01/01 to 2019/07/17. Information was extracted from the abstracts according to a modified Consolidated Standards of Reporting Trials (CONSORT) guideline checklist. The data was analyzed using descriptive statistical analysis and the statistical associations were examined using the linear regression analysis (P <0.05).

Results

This study retrieved 1715 articles and 249 of them were finally included. The average overall CONSORT score was 15.6 ± 3.4, which represented 40.9% (±0.6) of CONSORT criteria filling. The reporting rate of some items (trial design, numbers analyzed, confidence intervals, intention-to-treat analysis or per-protocol analysis, harms, registration) was less than 30%. The adequate reporting rate of some items (participants, randomization, numbers analyzed, confidence intervals, intention-to-treat analysis or per protocol analysis) was no more than 4%. None of the abstracts reported funding. According to the multivariable linear regression results, number of authors (P=0.030), word count (P <0.001), continent (P=0.003), structured format (P <0.001), type of periodontal disease (P <0.001) and international collaboration (P=0.023) have a significant association with reporting quality.

Conclusions

The quality of RCT abstracts on drug therapy of periodontal disease in SCI dental journals remained suboptimal. More efforts should be made to improve RCT abstracts reporting quality.

Key words:Abstracts, RCT, drug therapy, periodontal disease, CONSORT, reporting quality assessment.

Using the full PICO model as a search tool for systematic reviews resulted in lower recall for some PICO elements

OBJECTIVES

The use of the four-part PICO model to facilitate search strategy development for a precise answer is recommended for structuring searches for systematic reviews. Existing guidelines generally recommend that a search strategy should include the population, intervention(s), and types of study design. Consequently, comparison and outcome are not recommended as a part of the search strategy. There is evidence that comparison and particularly outcome is not represented in enough detail, but this needs to be confirmed.

STUDY DESIGN AND SETTING

The present study examines the presence of PICO elements in the records in two commonly used databases for health sciences research: Embase and PubMed. We examine the field of upper GI and pancreatic diseases as well as the field of pregnancy and childbirth by extracting the included studies as well as the related PICO elements from a random selection of Cochrane reviews within these two areas.

RESULTS

We find that the PICO elements C and O had a lower retrieval potential across the two Cochrane groups and databases also when combining text words and subject headings. In particular, we find a lower retrieval when searching for both primary and secondary outcomes.

CONCLUSION

Our results support the existing recommendation not to search for outcomes.

Abstracts of published randomised controlled trials in Endodontics: Reporting quality and spin

AIMS

To assess the reporting quality of recently published randomised controlled trial (RCT) abstracts in Endodontics, to investigate factors associated with reporting quality, and to evaluate the existence and characteristics of spin. Spin refers to reporting strategies that distort study results and misguide readers.

METHODOLOGY

The PubMed database was searched to identify abstracts of RCTs in the field of Endodontics published during 2017 to 2018. Two authors assessed the reporting quality of each included abstract using the original 16-item CONSORT for Abstracts checklist, with the overall quality score (OQS, range: 0 to 16) being the primary outcome measure. For each individual item, a score of '1' was given if it was described adequately, and '0' if the description was inadequate. Linear regression analyses were conducted to identify factors associated with reporting quality. For the evaluation of spin, two authors selected parallel-group RCTs with a nonsignificant primary outcome from the included abstracts, and evaluated independently the existence and characteristics of spin among these abstracts.

RESULTS

A total of 162 abstracts were included for assessment of reporting, for which the mean OQS was 3.97 (SD, 1.30; 95 % CI, 3.77 to 4.17). According to multivariable analysis, origin from Europe (P=0.001) and reporting of the exact P value (P=0.020) were significantly associated with better reporting. Forty abstracts with statistically nonsignificant results for their primary outcome were included for spin evaluation, among which 34 (85.0%) had at least one type of spin. Thirty-two abstracts (94.1%) had spin in their conclusions section, and six abstracts (17.6%) had spin in the results section.

CONCLUSIONS

The reporting quality of RCT abstracts in Endodontics needs to be improved. The occurrence rate of spin in the sample of abstracts of RCTs in the field of Endodontics was high. Relevant stakeholders are recommended to be familiar with the CONSORT for Abstracts guideline and develop active strategies to ensure its implementation.

Reporting sample size calculations for randomized controlled trials published in nursing journals: A cross-sectional study

BACKGROUND

Prior sample size calculation is essential to ensure that a randomized controlled trial (RCT) has enough power to detect any statistical differences between two groups while not over-recruiting participants. However, the compliance among RCTs published in nursing field is unknown.

OBJECTIVE

To describe the reporting of sample size methodology and parameters used in RCTs published in nursing journals.

DESIGN

A cross-sectional database search of all RCTs published in nursing journals was conducted.

SETTING

116 journals in the category of nursing.

PARTICIPANTS

Not applicable.

METHODS

A database search was conducted to identify all RCTs published in nursing journals from January 2016 to December 2016. Two-arm RCTs were reviewed to see if sample size estimation was mentioned in the text and if the parameters were sufficient for the estimation. For RCTs with effect size, sample sizes were recomputed and compared with the reported size.

RESULTS

Two hundred and twenty-three RCTs were included in this study, and 143 (64.1%) studies mentioned how they obtained their sample sizes. Among these 143 studies, 132 (92.3%), 133 (93.0%), 33 (23.1%), and 84 (58.7%) specified their levels of significance (α), powers, tails of the test, and effect size related information, respectively. Only 22 (15.4%) provided all the necessary parameters to compute their sample sizes. Out of the 84 RCTs with effect size information, 49 (58.3%) had a relative difference of less than 25%.

DISCUSSION

Around 36% of the RCTs published in nursing journals did not report how they reached their sample sizes. For those that had reported, only 15% provided all the necessary parameters to re-compute their sizes. It is concluded that the methodology and parameters used for sample size determination are inadequately reported in RCTs published in nursing journals.

Reporting quality of randomised controlled trial abstracts presented at the SLEEP Annual Meetings: a cross-sectional study

OBJECTIVES

To evaluate the reporting quality of randomised controlled trial (RCT) abstracts presented at a leading international conference in sleep medicine (the SLEEP Annual Meeting), and to investigate the association between potential predictors and the reporting quality of trial abstracts in this field.

DESIGN

Cross-sectional, research on research study.

METHODS

A handsearch of the 2016-2018 SLEEP Annual Meeting abstract books was carried out to identify abstracts describing RCTs. Quality of reporting was assessed with the original 17-item CONSORT for Abstracts checklist. Univariable and multivariable linear regression analyses were performed to identify significant predictors of reporting quality. In addition, risk ratios were used to analyse the adequate reporting rate of each quality item by type of intervention and funding status.

PRIMARY AND SECONDARY OUTCOME MEASURES

The overall quality score (OQS, range 0-17) in accordance with the CONSORT for Abstracts checklist (primary outcome), and the adequate reporting rate of each checklist item (secondary outcome).

RESULTS

A total of 176 RCT abstracts were included and assessed. The mean OQS was 5.53 (95% CI 5.30 to 5.76). Only three quality items (objective, conclusions and funding) were adequately reported in most abstracts (>75%). None of the abstracts adequately reported authors, randomisation or outcome in the results section. According to the multivariable analysis, pharmacological interventions (p=0.018) and funding from the industry (p=0.025) were significantly associated with better reporting quality.

CONCLUSIONS

The reporting quality of RCT abstracts presented at SLEEP Annual Meetings was suboptimal. Pharmacological intervention and funding from industry were significant predictors of better reporting quality. Joint efforts by authors and conference committees are needed to enhance the reporting quality of RCT abstracts presented at sleep medicine conferences, and thereby reduce relevant research waste in this field.

The degree of adherence to CONSORT reporting guidelines for the abstracts of randomised clinical trials published in anaesthesia journals: A cross-sectional study of reporting adherence in 2010 and 2016

BACKGROUND

Abstracts are intended to be concise summaries of the entire randomised clinical trial (RCT). Despite their importance, few studies have examined the reporting quality of abstracts in the anaesthesiology literature.

OBJECTIVES

To examine the quality of RCT abstract reporting according to the CONSORT for Abstracts guidelines and determine whether recommended items omitted from the abstract were present in the body of the article.

DESIGN

A cross-sectional study of RCTs.

SETTING

This study was performed at the University of Western Ontario and University Hospital, London Health Sciences Centre.

PARTICIPANTS

All RCTs meeting inclusion criteria that were published in 2010 or 2016 in six general anaesthesiology journals (Anaesthesia, Anesthesia & Analgesia, Anesthesiology, British Journal of Anaesthesia, Canadian Journal of Anesthesia and European Journal of Anaesthesiology).

MAIN OUTCOME MEASURES

The 16 checklist items from the CONSORT for Abstracts statement were used to create a convenience score as a proxy for RCT abstract reporting quality, with each criterion measured as being reported in abstract, not reported in abstract but reported in full-text article, or not reported in abstract or full-text article.

RESULTS

Of the 395 RCTs identified, 219 were published in 2010 and 176 were published in 2016. Out of the maximum possible score of 16, the median abstract score increased from 4 points [interquartile range (IQR): 3 to 5] in 2010 to 6 points [IQR: 5 to 8] in 2016. Although most checklist items showed improvement from 2010 to 2016, around 75% of RCTs in 2016 met fewer than half of the 16 items with no RCTs reporting all 16 items in the abstract. A majority of the RCTs had the information present in the full-text. In 2016, only 71 out of 176 (40%) of RCTs reported outcomes conforming to the CONSORT guidelines (with an effect size and a confidence interval around the effect size) in the Abstract.

CONCLUSION

Abstracts for many anaesthesiology RCTs are incomplete selective summaries of the entire article.

Quality improvement in randomized controlled trial abstracts in prosthodontics since the publication of CONSORT guideline for abstracts: a systematic review

OBJECTIVES

This study aimed to compare the reporting quality of randomized controlled trial (RCT) abstracts in prosthodontics before and after the publication of Consolidated Standards of Reporting Trials (CONSORT) guideline for abstracts and identify the characteristics associated with better reporting quality.

SOURCES

PubMed was searched for RCT abstracts published from 2001 to 2007 (pre-CONSORT period) and from 2010 to 2016 (post-CONSORT period) in six leading prosthodontic journals.

STUDY SELECTION

After applying the inclusion/exclusion criteria, 131 RCT abstracts were selected. The t test was performed to compare the overall quality between the two periods. Univariable and multivariable linear regressions were used to identify any factors relating to the reporting quality. The level of significance was set at P < 0.05.

DATA

The investigators extracted data and scored the abstracts independently based on CONSORT. The mean overall CONSORT score was 5.20 and 6.11 in the pre- and post-CONSORT samples, respectively. Significant changes were observed in reporting for only three items: title, conclusions, and trial registration. Most abstracts adequately reported interventions, objectives, and conclusions (>90%), but failed to report recruitment and outcome in the results section (<3%). Funding was not reported in both periods. The reporting quality was related to a higher impact factor, structured format, and published after CONSORT.

CONCLUSIONS

The quality of RCT abstracts in prosthodontics improved over time, but adherence to the CONSORT guideline for abstracts was still suboptimal.

Structure formats of randomised controlled trial abstracts: a cross-sectional analysis of their current usage and association with methodology reporting

BACKGROUND

The reporting of randomised controlled trial (RCT) abstracts is of vital importance. The primary objective of this study was to investigate the association between structure format and RCT abstracts' quality of methodology reporting, informed by the current requirement and usage of structure formats by leading general medical/internal medicine journals (secondary objective).

METHODS

A two-part cross-sectional study. First, through hand searches, we identified all RCTs published in the top-50 high-impact general medical/internal medicine journals during July-December 2015 (n = 370), and retrieved the 'instructions to authors' of these journals. From these, we extracted the actual usage of structure formats and headings, as well as relevant journal policies. Then, after a pilot study and sample size calculation, we assessed the methodology reporting quality of 176 IMRaD (Introduction, Methods, Results, and Discussion) and 165 HS (Highly Structured) RCT abstracts sampled from 33 of the 50 selected journals, using a 9-item checklist developed based on the CONSORT for Abstracts guidelines (primary outcome: overall quality score, OQS; score range 0 to 9).

RESULTS

88% (324/370) of all identified RCT abstracts were structured, among which 66% (215/324) used the IMRaD format and 34% (109/324) used HS. According to journals' 'instructions to authors', 48% (24/50) journals required IMRaD, 32% (16/50) required HS, 8% (4/50) required unstructured, while the rest did not state any requirement on structure format. According to generalised estimation equation analysis adjusting for potential confounders and clustering effects, the OQS of HS abstracts was 0.5 (95% CI 0.1 to 1.0, p = 0.028) higher than IMRaD abstracts. More HS abstracts reported study setting (adjusted odds ratio, 4.2; 95% CI: 1.7 to 10.0; p = 0.001), definition of the main outcome measure (2.5; 1.3 to 4.9; p = 0.006) and the time point for main outcome assessment (3.0; 1.5 to 6.2; p = 0.002), whereas more IMRaD abstracts described the unit of randomisation (0.4; 0.3 to 0.8; p = 0.004).

CONCLUSIONS

For RCT abstracts, the IMRaD format is more frequently used and required by leading general medical/internal medicine journals than the HS format. Abstracts in the HS format report trial methodology more completely than those in the IMRaD format.