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1.  CONSORT 2010 Statement: updated guidelines for reporting parallel group randomised trials 
Trials  2010;11:32.
The CONSORT statement is used worldwide to improve the reporting of randomised controlled trials. Kenneth Schulz and colleagues describe the latest version, CONSORT 2010, which updates the reporting guideline based on new methodological evidence and accumulating experience.
To encourage dissemination of the CONSORT 2010 Statement, this article is freely accessible on bmj.com and will also be published in the Lancet, Obstetrics and Gynecology, PLoS Medicine, Annals of Internal Medicine, Open Medicine, Journal of Clinical Epidemiology, BMC Medicine, and Trials.
doi:10.1186/1745-6215-11-32
PMCID: PMC2857832  PMID: 20334632
2.  A systematic review of cluster randomised trials in residential facilities for older people suggests how to improve quality 
Background
Previous reviews of cluster randomised trials have been critical of the quality of the trials reviewed, but none has explored determinants of the quality of these trials in a specific field over an extended period of time. Recent work suggests that correct conduct and reporting of these trials may require more than published guidelines. In this review, our aim was to assess the quality of cluster randomised trials conducted in residential facilities for older people, and to determine whether (1) statistician involvement in the trial and (2) strength of journal endorsement of the Consolidated Standards of Reporting Trials (CONSORT) statement influence quality.
Methods
We systematically identified trials randomising residential facilities for older people, or parts thereof, without language restrictions, up to the end of 2010, using National Library of Medicine (Medline) via PubMed and hand-searching. We based quality assessment criteria largely on the extended CONSORT statement for cluster randomised trials. We assessed statistician involvement based on statistician co-authorship, and strength of journal endorsement of the CONSORT statement from journal websites.
Results
73 trials met our inclusion criteria. Of these, 20 (27%) reported accounting for clustering in sample size calculations and 54 (74%) in the analyses. In 29 trials (40%), methods used to identify/recruit participants were judged by us to have potentially caused bias or reporting was unclear to reach a conclusion. Some elements of quality improved over time but this appeared not to be related to the publication of the extended CONSORT statement for these trials. Trials with statistician/epidemiologist co-authors were more likely to account for clustering in sample size calculations (unadjusted odds ratio 5.4, 95% confidence interval 1.1 to 26.0) and analyses (unadjusted OR 3.2, 1.2 to 8.5). Journal endorsement of the CONSORT statement was not associated with trial quality.
Conclusions
Despite international attempts to improve methods in cluster randomised trials, important quality limitations remain amongst these trials in residential facilities. Statistician involvement on trial teams may be more effective in promoting quality than further journal endorsement of the CONSORT statement. Funding bodies and journals should promote statistician involvement and co-authorship in addition to adherence to CONSORT guidelines.
doi:10.1186/1471-2288-13-127
PMCID: PMC4015673  PMID: 24148859
Residential facilities; Older people; Cluster randomised trials
3.  Endorsement for improving the quality of reports on randomized controlled trials of traditional medicine journals in Korea: a systematic review 
Trials  2014;15(1):429.
The aim of this study was to assess the endorsement of reporting guidelines in Korean traditional medicine (TM) journals by reviewing their instructions to authors. We examined the instructions to authors in all of the TM journals published in Korea to assess the appropriate use of reporting guidelines for research studies. The randomized controlled trials (RCTs) published after 2010 in journals that endorsed reporting guidelines were obtained. The reporting quality was assessed using the following guidelines: the 38-item Consolidated Standards of Reporting Trials (CONSORT) statement for non-pharmacological trials (NPT); the 17-item Standards for Reporting Interventions in Clinical Trials of Acupuncture (STRICTA) statement, instead of the 5-item CONSORT for acupuncture trials; and the 22-item CONSORT extensions for herbal medicine trials. The overall item score was calculated and expressed as a proportion.One journal that endorsed reporting guidelines was identified. Twenty-nine RCTs published in this journal after 2010 met the selection criteria. General editorial policies such as those of the International Committee of Medical Journal Editors (ICMJE) were endorsed by 15 journals. In each of the CONSORT-NPT articles, 21.6 to 56.8% of the items were reported, with an average of 11.3 items (29.7%) being reported. In the 24 RCTs (24/29, 82.8%) appraised using the STRICTA items, an average of 10.6 items (62.5%) were addressed, with a range of 41.2 to 100%. For the herbal intervention reporting, 17 items (77.27%) were reported. In the RCT studies before and after the endorsement of CONSORT and STRICTA guidelines by each journal, all of the STRICTA items had significant improvement, whereas the CONSORT-NPT items improved without statistical significance.The endorsement of reporting guidelines is limited in the TM journals in Korea. Authors should adhere to the reporting guidelines, and editorial departments should refer authors to the various reporting guidelines to improve the quality of their articles.
doi:10.1186/1745-6215-15-429
PMCID: PMC4236494  PMID: 25373427
4.  Assessment of adherence to the CONSORT statement for quality of reports on randomized controlled trial abstracts from four high-impact general medical journals 
Trials  2012;13:77.
Background
The extended Consolidated Standards of Reporting Trials (CONSORT) Statement for Abstracts was developed to improve the quality of reports of randomized controlled trials (RCTs) because readers often base their assessment of a trial solely on the abstract. To date, few data exist regarding whether it has achieved this goal. We evaluated the extent of adherence to the CONSORT for Abstract statement for quality of reports on RCT abstracts by four high-impact general medical journals.
Methods
A descriptive analysis of published RCT abstracts in The New England Journal of Medicine (NEJM), The Lancet, The Journal of American Medical Association (JAMA), and the British Medical Journal (BMJ) in the year 2010 was conducted by two reviewers, independently extracting data from a MEDLINE/PubMed search.
Results
We identified 271 potential RCT abstracts meeting our inclusion criteria. More than half of the abstracts identified the study as randomized in the title (58.7%; 159/271), reported the specific objective/hypothesis (72.7%; 197/271), described participant eligibility criteria with settings for data collection (60.9%; 165/271), detailed the interventions for both groups (90.8%; 246/271), and clearly defined the primary outcome (94.8%; 257/271). However, the methodological quality domains were inadequately reported: allocation concealment (11.8%; 32/271) and details of blinding (21.0%; 57/271). Reporting the primary outcome results for each group was done in 84.1% (228/271). Almost all of the abstracts reported trial registration (99.3%; 269/271), whereas reports of funding and of harm or side effects from the interventions were found in only 47.6% (129/271) and 42.8% (116/271) of the abstracts, respectively.
Conclusions
These findings show inconsistencies and non-adherence to the CONSORT for abstract guidelines, especially in the methodological quality domains. Improvements in the quality of RCT reports can be expected by adhering to existing standards and guidelines as expressed by the CONSORT group.
doi:10.1186/1745-6215-13-77
PMCID: PMC3469340  PMID: 22676267
Randomized controlled trials; CONSORT for abstracts; Quality of reports; General medical journals
5.  CONSORT 2010 Statement: updated guidelines for reporting parallel group randomised trials 
The CONSORT statement is used worldwide to improve the reporting of randomised controlled trials. Kenneth Schulz and colleagues describe the latest version, CONSORT 2010, which updates the reporting guideline based on new methodological evidence and accumulating experience
doi:10.1136/bmj.c332
PMCID: PMC2844940  PMID: 20332509
6.  Conflicts of Interest at Medical Journals: The Influence of Industry-Supported Randomised Trials on Journal Impact Factors and Revenue – Cohort Study 
PLoS Medicine  2010;7(10):e1000354.
Andreas Lundh and colleagues investigated the effect of publication of large industry-supported trials on citations and journal income, through reprint sales, in six general medical journals
Background
Transparency in reporting of conflict of interest is an increasingly important aspect of publication in medical journals. Publication of large industry-supported trials may generate many citations and journal income through reprint sales and thereby be a source of conflicts of interest for journals. We investigated industry-supported trials' influence on journal impact factors and revenue.
Methods and Findings
We sampled six major medical journals (Annals of Internal Medicine, Archives of Internal Medicine, BMJ, JAMA, The Lancet, and New England Journal of Medicine [NEJM]). For each journal, we identified randomised trials published in 1996–1997 and 2005–2006 using PubMed, and categorized the type of financial support. Using Web of Science, we investigated citations of industry-supported trials and the influence on journal impact factors over a ten-year period. We contacted journal editors and retrieved tax information on income from industry sources. The proportion of trials with sole industry support varied between journals, from 7% in BMJ to 32% in NEJM in 2005–2006. Industry-supported trials were more frequently cited than trials with other types of support, and omitting them from the impact factor calculation decreased journal impact factors. The decrease varied considerably between journals, with 1% for BMJ to 15% for NEJM in 2007. For the two journals disclosing data, income from the sales of reprints contributed to 3% and 41% of the total income for BMJ and The Lancet in 2005–2006.
Conclusions
Publication of industry-supported trials was associated with an increase in journal impact factors. Sales of reprints may provide a substantial income. We suggest that journals disclose financial information in the same way that they require them from their authors, so that readers can assess the potential effect of different types of papers on journals' revenue and impact.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Medical journals publish many different types of papers that inform doctors about the latest research advances and the latest treatments for their patients. They publish articles that describe laboratory-based research into the causes of diseases and the identification of potential new drugs. They publish the results of early clinical trials in which a few patients are given a potential new drug to check its safety. Finally and most importantly, they publish the results of randomized controlled trials (RCTs). RCTs are studies in which large numbers of patients are randomly allocated to different treatments without the patient or the clinician knowing the allocation and the efficacy of the various treatments compared. RCTs are best way of determining whether a new drug is effective and have to be completed before a drug can be marketed. Because RCTs are very expensive, they are often supported by drug companies. That is, drug companies provide grants or drugs for the trial or assist with data analysis and/or article preparation.
Why Was This Study Done?
Whenever a medical journal publishes an article, the article's authors have to declare any conflicts of interest such as financial gain from the paper's publication. Conflict of interest statements help readers assess papers—an author who owns the patent for a drug, for example, might put an unduly positive spin on his/her results. The experts who review papers for journals before publication provide similar conflict of interest statements. But what about the journal editors who ultimately decide which papers get published? The International Committee of Medical Journal Editors (ICMJE), which produces medical publishing guidelines, states that: “Editors who make final decisions about manuscripts must have no personal, professional, or financial involvement in any of the issues that they might judge.” However, the publication of industry-supported RCTs might create “indirect” conflicts of interest for journals by boosting the journal's impact factor (a measure of a journal's importance based on how often its articles are cited) and its income through the sale of reprints to drug companies. In this study, the researchers investigate whether the publication of industry-supported RCTs influences the impact factors and finances of six major medical journals.
What Did the Researchers Do and Find?
The researchers determined which RCTs published in the New England Journal of Medicine (NEJM), the British Medical Journal (BMJ), The Lancet, and three other major medical journals in 1996–1997 and 2005–2006 were supported wholly, partly, or not at all by industry. They then used the online academic citation index Web of Science to calculate an approximate impact factor for each journal for 1998 and 2007 and calculated the effect of the published RCTs on the impact factor. The proportion of RCTs with sole industry support varied between journals. Thus, 32% of the RCTs published in the NEJM during both two-year periods had industry support whereas only 7% of the RCTs published in the BMJ in 2005–2006 had industry support. Industry-supported trials were more frequently cited than RCTs with other types of support and omitting industry-supported RCTs from impact factor calculations decreased all the approximate journal impact factors. For example, omitting all RCTs with industry or mixed support decreased the 2007 BMJ and NEJM impact factors by 1% and 15%, respectively. Finally, the researchers asked each journal's editor about their journal's income from industry sources. For the BMJ and The Lancet, the only journals that provided this information, income from reprint sales was 3% and 41%, respectively, of total income in 2005–2006.
What Do These Findings Mean?
These findings show that the publication of industry-supported RCTs was associated with an increase in the approximate impact factors of these six major medical journals. Because these journals publish numerous RCTs, this result may not be generalizable to other journals. These findings also indicate that income from reprint sales can be a substantial proportion of a journal's total income. Importantly, these findings do not imply that the decisions of editors are affected by the possibility that the publication of an industry-supported trial might improve their journal's impact factor or income. Nevertheless, the researchers suggest, journals should live up to the same principles related to conflicts of interest as those that they require from their authors and should routinely disclose information on the source and amount of income that they receive.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000354.
This study is further discussed in a PLoS Medicine Perspective by Harvey Marcovitch
The International Committee of Medical Journal Editors provides information about the publication of medical research, including conflicts of interest
The World Association of Medical Editors also provides information on conflicts of interest in medical journals
Information about impact factors is provided by Thomson Reuters, a provider of intelligent information for businesses and professionals; Thomson Reuters also runs Web of Science
doi:10.1371/journal.pmed.1000354
PMCID: PMC2964336  PMID: 21048986
7.  Assessment of the Reporting Quality of Randomized Controlled Trials on Treatment of Coronary Heart Disease with Traditional Chinese Medicine from the Chinese Journal of Integrated Traditional and Western Medicine: A Systematic Review 
PLoS ONE  2014;9(1):e86360.
Background
Due to language limitations, little is known about the reporting quality of randomized clinical trials (RCTs) on the treatment of coronary heart disease (CHD) with traditional Chinese medicine (TCM) in Chinese Journal of Integrated Traditional and Western Medicine (CJITWM).
Objective
In this study, we utilized the CONSORT 2010 statement to understand the reporting quality of RCTs on CHD with TCM from the CJITWM.
Methods
The China National Knowledge Infrastructure (CNKI) electronic database was searched for CJITWM RCTs on the treatment of CHD with TCM, published between Janurary 1, 2006 and December 31, 2011. We excluded articles reported as “animal studies,” “topic review,” “diagnostic test,” “editorials,” or “others.” The CONSORT checklist was applied to evaluate the reporting quality of all eligible articles by two independent authors after extensive discussion. Each item was graded as either “yes” or “no” depending on whether the authors had reported it or not.
Results
We identified 21 articles meeting our inclusion criteria. The percentage of 11 of the 37 items was 4.8∼95.2%, 14 of the 37 items were reported in all included articles, while 12 items were not mentioned at all. The average reporting percentage for the “title and abstract” section was 52.4%, for the “introduction” section 100.0%, for the “methods” section 45.4%, for the “results” section 57.1%, for the “discussion” section 79.4%, and for the “other information” section 17.5%.
Conclusion
In general, the reviewed RCTs were not consistent with the CONSORT 2010 statement. Authors should adhere to the CONSORT statement in reporting RCTs; editorial departments may consider the CONSORT statement as a guideline and should instruct authors to write manuscripts, and reviewers to judge them according to CONSORT statutes.
doi:10.1371/journal.pone.0086360
PMCID: PMC3904907  PMID: 24489719
8.  Endorsement of the CONSORT Statement by high impact factor medical journals: a survey of journal editors and journal 'Instructions to Authors' 
Trials  2008;9:20.
Background
The CONSORT Statement provides recommendations for reporting randomized controlled trials. We assessed the extent to which leading medical journals that publish reports of randomized trials incorporate the CONSORT recommendations into their journal and editorial processes.
Methods
This article reports on two observational studies. Study 1: We examined the online version of 'Instructions to Authors' for 165 high impact factor medical journals and extracted all text mentioning the CONSORT Statement or CONSORT extension papers. Any mention of the International Committee of Medical Journal Editors (ICMJE) or clinical trial registration were also sought and extracted. Study 2: We surveyed the editor-in-chief, or editorial office, for each of the 165 journals about their journal's endorsement of CONSORT recommendations and its incorporation into their editorial and peer-review processes.
Results
Study 1: Thirty-eight percent (62/165) of journals mentioned the CONSORT Statement in their online 'Instructions to Authors'; of these 37% (23/62) stated this was a requirement, 63% (39/62) were less clear in their recommendations. Very few journals mentioned the CONSORT extension papers. Journals that referred to CONSORT were more likely to refer to ICMJE guidelines (RR 2.16; 95% CI 1.51 to 3.08) and clinical trial registration (RR 3.67; 95% CI 2.36 to 5.71) than those journals which did not.
Study 2: Thirty-nine percent (64/165) of journals responded to the on-line survey, the majority were journal editors. Eighty-eight percent (50/57) of journals recommended authors comply with the CONSORT Statement; 62% (35/56) said they would require this. Forty-one percent (22/53) reported incorporating CONSORT into their peer-review process and 47% (25/53) into their editorial process. Eighty-one percent (47/58) reported including CONSORT in their 'Instructions to Authors' although there was some inconsistency when cross checking information on the journal's website. Sixty-nine percent (31/45) of journals recommended authors comply with the CONSORT extension for cluster trials, 60% (27/45) for harms and 42% (19/45) for non-inferiority and equivalence trials. Few journals mentioned these extensions in their 'Instructions to Authors'.
Conclusion
Journals should be more explicit in their recommendations and expectations of authors regarding the CONSORT Statement and related CONSORT extensions papers.
doi:10.1186/1745-6215-9-20
PMCID: PMC2359733  PMID: 18423021
9.  Adherence of trials of operative intervention to the CONSORT statement extension for non-pharmacological treatments: a comparative before and after study 
INTRODUCTION
Use of the Consolidated Standards of Reporting Trials (CONSORT) statement has been shown to improve the reporting of randomised controlled trials and it is endorsed by leading surgical journals. The CONSORT statement for non-pharmacological treatment (CONSORT-NPT) provides specific items to aid in the reporting of trials of operative intervention. This study compares the reporting practice of trials of operative intervention published in time periods before and after publication of the CONSORT-NPT statement.
METHODS
A 30-point checklist containing the salient CONSORT-NPT items was designed and the adherence of trials meeting the inclusion criteria determined independently by two authors.
RESULTS
There was a significant improvement of 3.95 points in the mean CONSORT-NPT score from 2004 to 2010 (95% confidence interval: 3.61–4.29, p<0.001). This related specifically to items present in the original CONSORT statement rather than to CONSORT-NPT items, which remained poorly reported in 2010. The mean CONSORT-NPT score was 17.5 (standard deviation [SD]: 4.5) for trials published in CONSORT endorsing journals compared with 15.6 (SD: 4.0) for those that did not mention endorsement of the CONSORT statement although this was not a significant difference (p=0.064).
CONCLUSIONS
Although there has been a significant improvement in the reporting of trials of operative intervention published in the surgical literature since 2004, items specific to the CONSORT-NPT extension remain underreported. Improved awareness of this important addition to the CONSORT statement throughout the surgical community and its endorsement by surgical journals will help to improve the reporting practice of trials of operative intervention.
doi:10.1308/003588412X13171221592339
PMCID: PMC3954318  PMID: 22943327
CONSORT; Randomised controlled trial; Publishing/standards; Research design
10.  Effect of editors’ implementation of CONSORT guidelines on the reporting of abstracts in high impact medical journals: interrupted time series analysis  
Objective To investigate the effect of the CONSORT for Abstracts guidelines, and different editorial policies used by five leading general medical journals to implement the guidelines, on the reporting quality of abstracts of randomised trials.
Design Interrupted time series analysis.
Sample We randomly selected up to 60 primary reports of randomised trials per journal per year from five high impact, general medical journals in 2006-09, if indexed in PubMed with an electronic abstract. We excluded reports that did not include an electronic abstract, and any secondary trial publications or economic analyses. We classified journals in three categories: those not mentioning the guidelines in their instructions to authors (JAMA and New England Journal of Medicine), those referring to the guidelines in their instructions to authors but with no specific policy to implement them (BMJ), and those referring to the guidelines in their instructions to authors with an active policy to implement them (Annals of Internal Medicine and Lancet). Two authors extracted data independently using the CONSORT for Abstracts checklist.
Main outcome Mean number of CONSORT items reported in selected abstracts, among nine items reported in fewer than 50% of the abstracts published across the five journals in 2006.
Results We assessed 955 reports of abstracts of randomised trials. Journals with an active policy to enforce the guidelines showed an immediate increase in the level of mean number of items reported (increase of 1.50 items; P=0.0037). At 23 months after publication of the guidelines, the mean number of items reported per abstract for the primary outcome was 5.41 of nine items, a 53% increase compared with the expected level estimated on the basis of pre-intervention trends. The change in level or trend did not increase in journals with no policy to enforce the guidelines (BMJ, JAMA, and New England Journal of Medicine).
Conclusion Active implementation of the CONSORT for Abstracts guidelines by journals can lead to improvements in the reporting of abstracts of randomised trials.
doi:10.1136/bmj.e4178
PMCID: PMC3382226  PMID: 22730543
11.  Differences in Reporting of Analyses in Internal Company Documents Versus Published Trial Reports: Comparisons in Industry-Sponsored Trials in Off-Label Uses of Gabapentin 
PLoS Medicine  2013;10(1):e1001378.
Using documents obtained through litigation, S. Swaroop Vedula and colleagues compared internal company documents regarding industry-sponsored trials of off-label uses of gabapentin with the published trial reports and find discrepancies in reporting of analyses.
Background
Details about the type of analysis (e.g., intent to treat [ITT]) and definitions (i.e., criteria for including participants in the analysis) are necessary for interpreting a clinical trial's findings. Our objective was to compare the description of types of analyses and criteria for including participants in the publication (i.e., what was reported) with descriptions in the corresponding internal company documents (i.e., what was planned and what was done). Trials were for off-label uses of gabapentin sponsored by Pfizer and Parke-Davis, and documents were obtained through litigation.
Methods and Findings
For each trial, we compared internal company documents (protocols, statistical analysis plans, and research reports, all unpublished), with publications. One author extracted data and another verified, with a third person verifying discordant items and a sample of the rest. Extracted data included the number of participants randomized and analyzed for efficacy, and types of analyses for efficacy and safety and their definitions (i.e., criteria for including participants in each type of analysis). We identified 21 trials, 11 of which were published randomized controlled trials, and that provided the documents needed for planned comparisons. For three trials, there was disagreement on the number of randomized participants between the research report and publication. Seven types of efficacy analyses were described in the protocols, statistical analysis plans, and publications, including ITT and six others. The protocol or publication described ITT using six different definitions, resulting in frequent disagreements between the two documents (i.e., different numbers of participants were included in the analyses).
Conclusions
Descriptions of analyses conducted did not agree between internal company documents and what was publicly reported. Internal company documents provide extensive documentation of methods planned and used, and trial findings, and should be publicly accessible. Reporting standards for randomized controlled trials should recommend transparent descriptions and definitions of analyses performed and which study participants are excluded.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
To be credible, published research must present an unbiased, transparent, and accurate description of the study methods and findings so that readers can assess all relevant information to make informed decisions about the impact of any conclusions. Therefore, research publications should conform to universally adopted guidelines and checklists. Studies to establish whether a treatment is effective, termed randomized controlled trials (RCTs), are checked against a comprehensive set of guidelines: The robustness of trial protocols are measured through the Standard Protocol Items for Randomized Trials (SPIRIT), and the Consolidated Standards of Reporting Trials (CONSORT) statement (which was constructed and agreed by a meeting of journal editors in 1996, and has been updated over the years) includes a 25-point checklist that covers all of the key points in reporting RCTs.
Why Was This Study Done?
Although the CONSORT statement has helped improve transparency in the reporting of the methods and findings from RCTs, the statement does not define how certain types of analyses should be conducted and which patients should be included in the analyses, for example, in an intention-to-treat analysis (in which all participants are included in the data analysis of the group to which they were assigned, whether or not they completed the intervention given to the group). So in this study, the researchers used internal company documents released in the course of litigation against the pharmaceutical company Pfizer regarding the drug gabapentin, to compare between the internal and published reports the reporting of the numbers of participants, the description of the types of analyses, and the definitions of each type of analysis. The reports involved studies of gabapentin used for medical reasons not approved for marketing by the US Food and Drug Administration, known as “off-label” uses.
What Did the Researchers Do and Find?
The researchers identified trials sponsored by Pfizer relating to four off-label uses of gabapentin and examined the internal company protocols, statistical analysis plans, research reports, and the main publications related to each trial. The researchers then compared the numbers of participants randomized and analyzed for the main (primary) outcome and the type of analysis for efficacy and safety in both the internal research report and the trial publication. The researchers identified 21 trials, 11 of which were published RCTs that had the associated documents necessary for comparison.
The researchers found that in three out of ten trials there were differences in the internal research report and the main publication regarding the number of randomized participants. Furthermore, in six out of ten trials, the researchers were unable to compare the internal research report with the main publication for the number of participants analyzed for efficacy, because the research report either did not describe the primary outcome or did not describe the type of analysis. Overall, the researchers found that seven different types of efficacy analyses were described in the protocols, statistical analysis plans, and publications, including intention-to-treat analysis. However, the protocol or publication used six different descriptions for the intention-to-treat analysis, resulting in several important differences between the internal and published documents about the number of patients included in the analysis.
What Do These Findings Mean?
These findings from a sample of industry-sponsored trials on the off-label use of gabapentin suggest that when compared to the internal research reports, the trial publications did not always accurately reflect what was actually done in the trial. Therefore, the trial publication could not be considered to be an accurate and transparent record of the numbers of participants randomized and analyzed for efficacy. These findings support the need for further revisions of the CONSORT statement, such as including explicit statements about the criteria used to define each type of analysis and the numbers of participants excluded from each type of analysis. Further guidance is also needed to ensure consistent terminology for types of analysis. Of course, these revisions will improve reporting only if authors and journals adhere to them. These findings also highlight the need for all individual patient data to be made accessible to readers of the published article.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001378.
For more information, see the CONSORT statement website
The EQUATOR Network website is a resource center for the good reporting of health research studies and has more information about the SPIRIT initiative and the CONSORT statement
doi:10.1371/journal.pmed.1001378
PMCID: PMC3558476  PMID: 23382656
12.  Endorsement of the CONSORT Statement by High-Impact Medical Journals in China: A Survey of Instructions for Authors and Published Papers 
PLoS ONE  2012;7(2):e30683.
Background
The CONSORT Statement is a reporting guideline for authors when reporting randomized controlled trials (RCTs). It offers a standard way for authors to prepare RCT reports. It has been endorsed by many high-impact medical journals and by international editorial groups. This study was conducted to assess the endorsement of the CONSORT Statement by high-impact medical journals in China by reviewing their instructions for authors.
Methodology/Principal Findings
A total of 200 medical journals were selected according to the Chinese Science and Technology Journal Citation Reports, 195 of which publish clinical research papers. Their instructions for authors were reviewed and all texts mentioning the CONSORT Statement or CONSORT extension papers were extracted. Any mention of the Uniform Requirements for Manuscripts Submitted to Biomedical Journals (URM) developed by the International Committee of Medical Journal Editors (ICMJE) or ‘clinical trial registration’ was also extracted. For journals endorsing the CONSORT Statement, their most recently published RCT reports were retrieved and evaluated to assess whether the journals have followed what the CONSORT Statement required. Out of the 195 medical journals publishing clinical research papers, only six (6/195, 3.08%) mentioned ‘CONSORT’ in their instructions for authors; out of the 200 medical journals surveyed, only 14 (14/200, 7.00%) mentioned ‘ICMJE’ or ‘URM’ in their instructions for authors, and another five journals stated in their instructions for authors that clinical trials should have trial registration numbers and that priority would be given to clinical trials which had been registered. Among the 62 RCT reports published in the six journals endorsing the CONSORT Statement, 20 (20/62, 32.26%) contained flow diagrams and only three (3/62, 4.84%) provided trial registration information.
Conclusions/Significance
Medical journals in China endorsing either the CONSORT Statement or the ICMJE's URM constituted a small percentage of the total; all of these journals used ambiguous language regarding what was expected of authors.
doi:10.1371/journal.pone.0030683
PMCID: PMC3278410  PMID: 22348017
13.  Improving the reporting of pragmatic trials: an extension of the CONSORT statement 
Background The CONSORT statement is intended to improve reporting of randomised controlled trials and focuses on minimising the risk of bias (internal validity). The applicability of a trial’s results (generalisability or external validity) is also important, particularly for pragmatic trials. A pragmatic trial (a term first used in 1967 by Schwartz and Lellouch) can be broadly defined as a randomised controlled trial whose purpose is to inform decisions about practice. This extension of the CONSORT statement is intended to improve the reporting of such trials and focuses on applicability.
Methods At two, two-day meetings held in Toronto in 2005 and 2008, we reviewed the CONSORT statement and its extensions, the literature on pragmatic trials and applicability, and our experiences in conducting pragmatic trials.
Recommendations We recommend extending eight CONSORT checklist items for reporting of pragmatic trials: the background, participants, interventions, outcomes, sample size, blinding, participant flow, and generalisability of the findings. These extensions are presented, along with illustrative examples of reporting, and an explanation of each extension. Adherence to these reporting criteria will make it easier for decision makers to judge how applicable the results of randomised controlled trials are to their own conditions. Empirical studies are needed to ascertain the usefulness and comprehensiveness of these CONSORT checklist item extensions. In the meantime we recommend that those who support, conduct, and report pragmatic trials should use this extension of the CONSORT statement to facilitate the use of trial results in decisions about health care.
Pragmatic trials are designed to inform decisions about practice, but poor reporting can reduce their usefulness. The CONSORT and Practihc groups describe modifications to the CONSORT guidelines to help readers assess the applicability of the results
doi:10.1136/bmj.a2390
PMCID: PMC3266844  PMID: 19001484
14.  Assessment of the quality of reporting in randomised controlled trials of acupuncture in the Korean literature using the CONSORT statement and STRICTA guidelines 
BMJ Open  2014;4(7):e005068.
Objectives
This study aims to assess the completeness of reporting of randomised controlled trials (RCTs) of acupuncture in the Korean literature.
Design
Systematic review.
Methods
We searched 12 Korean databases and 7 Korean journals to identify eligible RCTs of acupuncture published from 1996 to July 2011. We used the Consolidated Standards of Reporting Trials (CONSORT) checklist for parallel RCTs and the revised STandards for Reporting Interventions in Clinical Trials of Acupuncture (STRICTA) to assess the quality of reporting in Korean RCTs. We compared the completeness of reporting of CONSORT and STRICTA items in RCTs published in two time periods (1996–2004 referred to as the early period and 2005–2011 referred to as the late period).
Results
We analysed 146 eligible RCTs using the CONSORT statement concerning RCTs of both needling and non-needling acupuncture and the STRICTA guidelines for 90 trials of needling acupuncture. Among the 103 RCTs in the late period, the proportion of RCTs that completely reported the CONSORT items of outcome definition (15.5%), sample size calculation (2.9%), randomisation (56%), allocation concealment (5.8%), implementation of allocation (11.7%), outcome assessor blinding (20.3%), flow of participants (25.2%), number of participants analysed (19.4%), ancillary analyses (0.0%), adverse events (24.3%), generalisability of findings (1.9%) and overall evidence (32.0%) remained small. Among the 61 RCTs of needling acupuncture in the late period, the STRICTA items of setting/context (24.6%) and practitioner background (27.9%) showed incomplete reporting. The completeness of reporting improved over time in several CONSORT and STRICTA items.
Conclusions
The completeness of reporting of Korean RCTs of acupuncture was suboptimal according to the CONSORT and revised STRICTA statements. Trial authors and journal editors should use the CONSORT statement and STRICTA guidelines for transparent reporting in Korean RCTs of acupuncture. The endorsement of the CONSORT and revised STRICTA statements in author instructions is also required.
doi:10.1136/bmjopen-2014-005068
PMCID: PMC4120411  PMID: 25079926
Complementary Medicine; Education & Training (see Medical Education & Training); Epidemiology
15.  Improvement of quality of reporting in randomised controlled trials to prevent hypotension after spinal anaesthesia for caesarean section 
Gynecological Surgery  2010;8(2):121-127.
Hypotension is a frequent complication of spinal anaesthesia for caesarean section and can threaten the well-being of the unborn child. Numerous randomised controlled trials (RCTs) dealt with measures to prevent hypotension. The aim of this study was to determine the reporting quality of RCTs using the Consolidated Standards of Reporting Trials (CONSORT) statement since low quality can lend false credibility to a study and overestimate the effect of an intervention. We performed a systematic literature search in PubMed to identify relevant RCTs in a pre-CONSORT period (1990–1994) and a post-CONSORT period (2004–2008). A comparative evaluation was done between the two periods, and the trials were assessed for compliance with each of the 22 CONSORT items. A total of 37 RCTs was identified. The CONSORT score increased significantly (p < 0.05) from 66.7% (±12.5%) in the pre-CONSORT period to 87.4% (±6.9%) in the post-CONSORT period. A statistically significant improvement was found for eight items, including randomization, blinding and intention-to-treat analysis. The CONSORT score in the post-CONSORT era was fairly good, also in comparison to other medical fields. In the post-CONSORT era, reporting of important items improved, in particular in the domains that are crucial to avoid bias and to improve internal validity. Use of CONSORT should be encouraged in order to keep or even improve the reporting quality.
doi:10.1007/s10397-010-0648-2
PMCID: PMC3083505  PMID: 21654900
Caesarean section; Spinal anaesthesia; Hypotension; Randomised controlled; Trials; CONSORT statement
16.  Protocol for CONSORT-SPI: an extension for social and psychological interventions 
Background
Determining the effectiveness of social and psychological interventions is important for improving individual and population health. Such interventions are complex and, where possible, are best evaluated by randomised controlled trials (RCTs). The use of research findings in policy and practice decision making is hindered by poor reporting of RCTs. Poor reporting limits the ability to replicate interventions, synthesise evidence in systematic reviews, and utilise findings for evidence-based policy and practice. The lack of guidance for reporting the specific methodological features of complex intervention RCTs contributes to poor reporting. We aim to develop an extension of the Consolidated Standards of Reporting Trials Statement for Social and Psychological Interventions (CONSORT-SPI).
Methods/design
This research project will be conducted in five phases. The first phase was the project launch, which consisted of the establishment of a Project Executive and International Advisory Group, and recruitment of journal editors and the CONSORT Group. The second phase involves a Delphi process that will generate a list of possible items to include in the CONSORT Extension. Next, there will be a formal consensus meeting to select the reporting items to add to, or modify for, the CONSORT-SPI Extension. Fourth, guideline documents will be written, including an explanation and elaboration (E&E) document that will provide detailed advice for each item and examples of good reporting. The final phase will comprise guideline dissemination, with simultaneous publication and endorsement of the guideline in multiple journals, endorsement by funding agencies, presentations at conferences and other meetings, and a dedicated website that will facilitate feedback about the guideline.
Conclusion
As demonstrated by previous CONSORT guidelines, the development of an evidence-based reporting guideline for social and psychological intervention RCTs should improve the accuracy, comprehensiveness, and transparency of study reports. This, in turn, promises to improve the critical appraisal of research and its use in policy and practice decision making. We invite readers to participate in the project by visiting our website (http://tinyurl.com/CONSORT-study).
doi:10.1186/1748-5908-8-99
PMCID: PMC3766255  PMID: 24004579
CONSORT-SPI; Randomised controlled trial; RCT; Reporting guidelines; Complex interventions
17.  A survey of instructions to authors in surgical journals on reporting by CONSORT and PRISMA 
INTRODUCTION
Guidance has been published on how best to report randomised controlled trials (Consolidated Standards of Reporting Trials – CONSORT) and systematic reviews (Preferred Reporting Items for Systematic Reviews and Meta-Analyses – PRISMA). The aim of this study was to establish to what extent surgical journals formally endorse CONSORT and PRISMA in the respective reporting of randomised controlled trials and systematic reviews.
METHODS
Overall, 136 surgical journals indexed in Journal Citation Reports® were studied. Author guidelines were scrutinised for the following guidance: conflict of interests (COI), the Uniform Requirements for Manuscripts (URM), clinical trial registration, CONSORT and PRISMA.
RESULTS
The frequency of guidance endorsement was found to be as follows: COI 82%, URM 62%, trial registration 32%, CONSORT 29% and PRISMA 10%. Journals with a higher impact were more likely to adopt trial registration, CONSORT and PRISMA. Journals with editorial offices in the UK were more likely to insist on disclosure of COI and to endorse CONSORT.
CONCLUSIONS
Guidelines produced to improve publication practice have not been implemented widely by surgical journals. This may contribute to an overall poorer quality of published research. Editors of surgical journals should uniformly endorse reporting guidance and update their instructions to authors to reflect this.
doi:10.1308/003588412X13373405386619
PMCID: PMC3954239
Editorial policies; Clinical trials; Conflict of interests; Journalism
18.  Does use of the CONSORT Statement impact the completeness of reporting of randomised controlled trials published in medical journals? A Cochrane reviewa 
Systematic Reviews  2012;1:60.
Background
The Consolidated Standards of Reporting Trials (CONSORT) Statement is intended to facilitate better reporting of randomised clinical trials (RCTs). A systematic review recently published in the Cochrane Library assesses whether journal endorsement of CONSORT impacts the completeness of reporting of RCTs; those findings are summarised here.
Methods
Evaluations assessing the completeness of reporting of RCTs based on any of 27 outcomes formulated based on the 1996 or 2001 CONSORT checklists were included; two primary comparisons were evaluated. The 27 outcomes were: the 22 items of the 2001 CONSORT checklist, four sub-items describing blinding and a ‘total summary score’ of aggregate items, as reported. Relative risks (RR) and 99% confidence intervals were calculated to determine effect estimates for each outcome across evaluations.
Results
Fifty-three reports describing 50 evaluations of 16,604 RCTs were assessed for adherence to at least one of 27 outcomes. Sixty-nine of 81 meta-analyses show relative benefit from CONSORT endorsement on completeness of reporting. Between endorsing and non-endorsing journals, 25 outcomes are improved with CONSORT endorsement, five of these significantly (α = 0.01). The number of evaluations per meta-analysis was often low with substantial heterogeneity; validity was assessed as low or unclear for many evaluations.
Conclusions
The results of this review suggest that journal endorsement of CONSORT may benefit the completeness of reporting of RCTs they publish. No evidence suggests that endorsement hinders the completeness of RCT reporting. However, despite relative improvements when CONSORT is endorsed by journals, the completeness of reporting of trials remains sub-optimal. Journals are not sending a clear message about endorsement to authors submitting manuscripts for publication. As such, fidelity of endorsement as an ‘intervention’ has been weak to date. Journals need to take further action regarding their endorsement and implementation of CONSORT to facilitate accurate, transparent and complete reporting of trials.
doi:10.1186/2046-4053-1-60
PMCID: PMC3564748  PMID: 23194585
CONSORT; Endorsement; Reporting guideline; Completeness of reporting
19.  Poor adherence of randomised trials in surgery to CONSORT guidelines for non-pharmacological treatments (NPT): a cross-sectional study 
BMJ Open  2013;3(12):e003898.
Objective
To systematically assess adherence of randomised trials in surgery to Consolidated Standards of Reporting Trials (CONSORT) guidelines for non-pharmacological treatments (NPT). Surgical trials are considered more difficult to design and execute than pharmacological trials. Furthermore, the original CONSORT statement does not address some aspects that are vital to the transparent reporting of surgical trials. The CONSORT-NPT extension was designed to address these issues but adherence in medical and surgical journals has not been assessed.
Design
Cross-sectional study.
Sample
We identified eight general medical and eight surgical journals, indexed in PubMed and published in 2011, with the highest impact factors in their respective categories.
Main outcomes
Adherence to CONSORT statement and CONSORT-NPT extension items.
Results
We identified 54 surgical trials (22 published in medical journals and 32 in surgical journals). There were eight items for which there was less than 30% overall compliance (seven were specific to the CONSORT-NPT extension). These seven items are related to: a full description of the care providers, centres and blinding status in the abstract (n=7/54, 13%), eligibility criteria for centres performing the interventions (n=13/54, 24%), how adherence of care providers with the protocol was assessed or enhanced (n=7/54, 13%), how clustering by care providers or centres was addressed as it relates to sample size (n=3/54, 6%), how care providers were allocated to each group (n=9/54, 17%), how clustering by care providers or centres was addressed as it relates to statistical methods (n=2/54, 4%), a description of care providers (case volume, qualification, expertise, etc) and centres (volume) in each group (n=0/54, 0%).
Conclusions
Adherence of surgical trials to CONSORT-NPT extension items is much poorer than to the standard CONSORT statement. Adherence also appears to be superior in general medical journals compared with surgical journals. Raising awareness and conducting qualitative research to identify areas for specific intervention will be important going forward.
doi:10.1136/bmjopen-2013-003898
PMCID: PMC3884742  PMID: 24353256
SURGERY
20.  The impact of the CONSORT Statement on reporting of Randomized Clinical Trials in Psychiatry 
Contemporary clinical trials  2008;30(2):116-122.
To determine whether the CONSORT recommendations influenced the quality of reporting of randomized controlled trials (RCTs) in the field of psychiatry, we evaluated the quality of clinical trial reports before and after the introduction of CONSORT statement. We selected seven high impact journals and retrieved the randomized, clinical trials in the field of psychiatry during the period of 1992–1996 (pre-CONSORT) and 2002–2007 (post-CONSORT).
Among the total 5,201 articles screened, 736 were identified and entered in our database. After critical review of the publications, 442 articles met the inclusion and exclusion criteria. The CONSORT Index (sum of 22 items of the checklist) during the post-CONSORT period was significantly higher than that during the pre-CONSORT period. However, over 40% of post-CONSORT studies did not adhere to CONSORT statement for reporting the process of randomization, and details of the process for obtaining informed consent were still insufficient. Furthermore, adherence to the CONSORT guidelines of reporting how blinding was accomplished and evaluated actually decreased after publication of the CONSORT statement. Although the overall quality of reporting on psychiatric RCTs generally improved after publication of the CONSORT statement, reporting the details of randomization, blinding, and obtaining informed consent remain insufficient.
doi:10.1016/j.cct.2008.11.004
PMCID: PMC3489160  PMID: 19070681
CONSORT statement; Randomized Clinical trial; Psychiatry
21.  Assessment of the Reporting Quality of Randomized Controlled Trials on the Treatment of Diabetes Mellitus with Traditional Chinese Medicine: A Systematic Review 
PLoS ONE  2013;8(7):e70586.
Background
After the publication of the CONSORT 2010 statement, few studies have been conducted to assess the reporting quality of randomized clinical trials (RCTs) on treatment of diabetes mellitus with Traditional Chinese Medicine (TCM) published in Chinese journals.
Objective
To investigate the current situation of the reporting quality of RCTs in leading medical journals in China with the CONSORT 2010 statement as criteria.
Methods
The China National Knowledge Infrastructure (CNKI) electronic database was searched for RCTs on the treatment of diabetes mellitus with TCM published in the Journal of Traditional Chinese Medicine, Chinese Journal of Integrated Traditional & Western Medicine, and the China Journal of Chinese Materia Medica from January to December 2011. We excluded trials reported as “animal studies”, “in vitro studies”, “case studies”, or “systematic reviews”. The CONSORT checklist was applied by two independent raters to evaluate the reporting quality of all eligible trials after discussing and comprehending the items thoroughly. Each item in the checklist was graded as either “yes” or “no” depending on whether it had been reported by the authors.
Results
We identified 27 RCTs. According to the 37 items in the CONSORT checklist, the average reporting percentage was 45.0%, in which the average reporting percentage for the “title and abstract”, the “introduction”, the “methods”, the “results”, the “discussion” and the “other information” was 33.3%, 88.9%, 36.4%, 54.4%, 71.6% and 14.8%, respectively. In the Journal of Traditional Chinese Medicine, Chinese Journal of Integrated Traditional & Western Medicine, and the China Journal of Chinese Materia Medica the average reporting percentage was 42.2%, 56.8%, and 46.0%, respectively.
Conclusions
The reporting quality of RCTs in these three journals was insufficient to allow readers to assess the validity of the trials. We recommend that editors require authors to use the CONSORT statement when reporting their trial results as a condition of publication.
doi:10.1371/journal.pone.0070586
PMCID: PMC3722156  PMID: 23894675
22.  Levels of evidence: a comparison between top medical journals and general pediatric journals 
BMC Pediatrics  2015;15:3.
Background
Given the large number of publications in all fields of practice, it is essential that clinicians focus on the resources that provide the highest level of evidence (LOE). We sought to determine the LOE that exists in the field of pediatrics, present in the general pediatric as well as high impact clinical literature.
Methods
Clinical pediatric literature, published between April 2011 and March 2012 inclusive in high-impact clinical journals (HICJ) (New England Journal of Medicine, Journal of the American Medical Association, & The Lancet) and the highest-impact general pediatric journals (GPJ) (Pediatrics, Journal of Pediatrics, & Archives of Pediatrics & Adolescent Medicine), was assessed. In addition to the LOE, articles were evaluated on criteria including subspecialty within pediatrics, number of authors, number of centers, and other parameters. Eligible level I randomized control trials were appraised using the Consolidated Standards of Reporting Trials (CONSORT) guidelines.
Results
Of 6511 articles screened, 804 met inclusion criteria (68 in HICJ and 736 in GPJ). On average, LOE in pediatrics-focused articles within The Lancet were significantly higher than all GPJ (p < 0.05). Average CONSORT scores were significantly higher in HICJ vs. GPJ (15.2 vs. 13.6, respectively, p < 0.001).
Conclusions
LOE and quality of randomized control trials within the pediatric field is highest within HICJ, however, only represent a small proportion of data published. Following CONSORT criteria, and promoting studies of high LOE may allow authors and readers to turn to journals and articles of greater clinical impact.
doi:10.1186/s12887-015-0324-9
PMCID: PMC4336754
Evidence-based medicine; Data quality; Journal impact factor
23.  Reporting Quality of Social and Psychological Intervention Trials: A Systematic Review of Reporting Guidelines and Trial Publications 
PLoS ONE  2013;8(5):e65442.
Background
Previous reviews show that reporting guidelines have improved the quality of trial reports in medicine, yet existing guidelines may not be fully suited for social and psychological intervention trials.
Objective/Design
We conducted a two-part study that reviewed (1) reporting guidelines for and (2) the reporting quality of social and psychological intervention trials.
Data Sources
(1) To identify reporting guidelines, we systematically searched multiple electronic databases and reporting guideline registries. (2) To identify trials, we hand-searched 40 journals with the 10 highest impact factors in clinical psychology, criminology, education, and social work.
Eligibility
(1) Reporting guidelines consisted of articles introducing a checklist of reporting standards relevant to social and psychological intervention trials. (2) Trials reported randomised experiments of complex interventions with psychological, social, or health outcomes.
Results
(1) We identified 19 reporting guidelines that yielded 147 reporting standards relevant to social and psychological interventions. Social and behavioural science guidelines included 89 standards not found in CONSORT guidelines. However, CONSORT guidelines used more recommended techniques for development and dissemination compared to other guidelines. (2) Our review of trials (n = 239) revealed that many standards were poorly reported, such as identification as a randomised trial in titles (20% reported the information) and abstracts (55%); information about blinding (15%), sequence generation (23%), and allocation concealment (17%); and details about actual delivery of experimental (43%) and control interventions (34%), participant uptake (25%), and service environment (28%). Only 11 of 40 journals referenced reporting guidelines in “Instructions to Authors.”
Conclusion
Existing reporting guidelines have important limitations in content, development, and/or dissemination. Important details are routinely missing from trial publications; most leading journals in social and behavioural sciences do not ask authors to follow reporting standards. Findings demonstrate a need to develop a CONSORT extension with updated standards for social and psychological intervention trials.
doi:10.1371/journal.pone.0065442
PMCID: PMC3666983  PMID: 23734256
24.  Internet-based randomised controlled trials for the evaluation of complementary and alternative medicines: probiotics in spondyloarthropathy 
Background
The clinical effectiveness of complementary and alternative medicines (CAMs) is widely debated because of a lack of clinical trials. The internet may provide an effective and economical approach for undertaking randomised controlled trials (RCTs) of low-risk interventions. We investigated whether the internet could be used to perform an internet-based RCT of a CAM fulfilling the revised CONSORT (Consolidated Standards of Reporting Trials) statement quality checklist for reporting of RCTs. A secondary aim was to examine the effect of probiotics compared to placebo in terms of well-being over 12 weeks.
Methods
People aged ≥18 years with confirmed spondyloarthropathy living in the United Kingdom with internet access were invited to participate in an internet-based RCT of probiotic compared to placebo for improving well-being and bowel symptoms. The intervention was a probiotic containing 4 strains of live bacteria or identical placebo taken by mouth daily for 3 months. The primary outcome measure was the performance of the trial according to the revised CONSORT statement.
Results
147 people were randomised into the trial. The internet-based trial of the CAM fulfilled the revised CONSORT statement such as efficient blinding, allocation concealment, intention to treat analysis and flow of participants through the trial. Recruitment of the required number of participants was completed in 19 months. Sixty-five percent (96/147) completed the entire 3 months of the trial. The trial was low cost and demonstrated that in an intention to treat analysis, probiotics did not improve well-being or bowel symptoms.
Conclusion
The internet-based RCT proved to be a successful and economical method for examining this CAM intervention. Recruitment, adherence and completion rate were all similar to those reported with conventional RCTs but at a fraction of the cost. Internet-based RCTs can fulfil all the criteria of the revised CONSORT statement and are an appropriate method for studying low-risk interventions.
Trial registration
ISRCTN36133252
doi:10.1186/1471-2474-9-4
PMCID: PMC2241591  PMID: 18190710
25.  A review of reporting of participant recruitment and retention in RCTs in six major journals 
Trials  2009;10:52.
Background
Poor recruitment and retention of participants in randomised controlled trials (RCTs) is problematic but common. Clear and detailed reporting of participant flow is essential to assess the generalisability and comparability of RCTs. Despite improved reporting since the implementation of the CONSORT statement, important problems remain. This paper aims: (i) to update and extend previous reviews evaluating reporting of participant recruitment and retention in RCTs; (ii) to quantify the level of participation throughout RCTs.
Methods
We reviewed all reports of RCTs of health care interventions and/or processes with individual randomisation, published July–December 2004 in six major journals. Short, secondary or interim reports, and Phase I/II trials were excluded. Data recorded were: general RCT details; inclusion of flow diagram; participant flow throughout trial; reasons for non-participation/withdrawal; target sample sizes.
Results
133 reports were reviewed. Overall, 79% included a flow diagram, but over a third were incomplete. The majority reported the flow of participants at each stage of the trial after randomisation. However, 40% failed to report the numbers assessed for eligibility. Percentages of participants retained at each stage were high: for example, 90% of eligible individuals were randomised, and 93% of those randomised were outcome assessed. On average, trials met their sample size targets. However, there were some substantial shortfalls: for example 21% of trials reporting a sample size calculation failed to achieve adequate numbers at randomisation, and 48% at outcome assessment. Reporting of losses to follow up was variable and difficult to interpret.
Conclusion
The majority of RCTs reported the flow of participants well after randomisation, although only two-thirds included a complete flow chart and there was great variability over the definition of "lost to follow up". Reporting of participant eligibility was poor, making assessments of recruitment practice and external validity difficult. Reporting of participant flow throughout RCTs could be improved by small changes to the CONSORT chart.
doi:10.1186/1745-6215-10-52
PMCID: PMC2717957  PMID: 19591685

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