Empirical evidence for selective reporting of outcomes in randomized trials: comparison of protocols to published articles. Undisclosed changes in outcomes in randomized controlled trials: an observational study. Adverse event reporting in publications compared with sponsor database for cancer clinical trials. Comparison of registered and published primary outcomes in randomized controlled trials. Reporting in randomized clinical trials improved after adoption of the CONSORT statement. Use of the CONSORT statement and quality of reports of randomized trials: a comparative before-and-after evaluation. Outcome reporting among drug trials registered in ClinicalTrials.gov. The reporting of methodological factors in randomized controlled trials and the association with a journal policy to promote adherence to the Consolidated Standards of Reporting Trials (CONSORT) checklist. Funding source, trial outcome and reporting quality: are they related? Results of a pilot study. Bias in reporting clinical trials. Publication and non-publication of clinical trials: longitudinal study of applications submitted to a research ethics committee. Are leading medical journals following their own policies on CONSORT reporting? Eligibility criteria for HIV clinical trials and generalizability of results: the gap between published reports and study protocols. Association of trial registration with the results and conclusions of published trials of new oncology drugs. Factors associated with failure to publish large randomized trials presented at an oncology meeting. CONSORT adoption and quality of reporting of randomized controlled trials: a systematic analysis in two dermatology journals.
Selective reporting of outcomes within published studies based on the nature or direction of their results has been widely suspected, but direct evidence of such bias is currently limited to case reports.
                To study empirically the extent and nature of outcome reporting bias in a cohort of randomized trials.
                Cohort study using protocols and published reports of randomized trials approved by the Scientific-Ethical Committees for Copenhagen and Frederiksberg, Denmark, in 1994-1995. The number and characteristics of reported and unreported trial outcomes were recorded from protocols, journal articles, and a survey of trialists. An outcome was considered incompletely reported if insufficient data were presented in the published articles for meta-analysis. Odds ratios relating the completeness of outcome reporting to statistical significance were calculated for each trial and then pooled to provide an overall estimate of bias. Protocols and published articles were also compared to identify discrepancies in primary outcomes.
                Completeness of reporting of efficacy and harm outcomes and of statistically significant vs nonsignificant outcomes; consistency between primary outcomes defined in the most recent protocols and those defined in published articles.
                One hundred two trials with 122 published journal articles and 3736 outcomes were identified. Overall, 50% of efficacy and 65% of harm outcomes per trial were incompletely reported. Statistically significant outcomes had a higher odds of being fully reported compared with nonsignificant outcomes for both efficacy (pooled odds ratio, 2.4; 95% confidence interval [CI], 1.4-4.0) and harm (pooled odds ratio, 4.7; 95% CI, 1.8-12.0) data. In comparing published articles with protocols, 62% of trials had at least 1 primary outcome that was changed, introduced, or omitted. Eighty-six percent of survey responders (42/49) denied the existence of unreported outcomes despite clear evidence to the contrary.
                The reporting of trial outcomes is not only frequently incomplete but also biased and inconsistent with protocols. Published articles, as well as reviews that incorporate them, may therefore be unreliable and overestimate the benefits of an intervention. To ensure transparency, planned trials should be registered and protocols should be made publicly available prior to trial completion. We wanted to investigate the frequency of undisclosed changes in the outcomes of randomized controlled trials (RCTs) between trial registration and publication.
                Using a retrospective, nonrandom, cross-sectional study design, we investigated RCTs published in consecutive issues of 5 major medical journals during a 6-month period and their associated trials registry entries. Articles were excluded if they did not have an available trial registry entry, did not have analyzable outcomes, or were secondary publications. The primary outcome was the proportion of publications in which the primary outcome of the trial was, without disclosure, changed between that recorded in the trial registry and that reported in the final publication. The secondary outcome was the proportion of publications in which the secondary outcome was changed without disclosure.
                We reviewed 158 reports of RCTs and included 110 in the analysis. In 34 (31%), a primary outcome had been changed, and in 77 (70%), a secondary outcome had been changed.
                There are substantial and important undisclosed changes made to the outcomes of published RCTs between trial registration and publication. This finding has important implications for the interpretation of trial results. Disclosure and discussion of changes would improve transparency in the performance and reporting of trials. Prospectively planned collection and analysis of adverse event (AE) data are essential parts of well-conducted clinical trials. The AE data in a trial sponsor's database should be comparable with what is stipulated in the protocol and with the AE data published. We examined whether the published AE data differ from those in the sponsor's database and from the data collection requirements stated in study protocols.
                We searched the National Cancer Institute (NCI) Clinical Data Update System (CDUS) for studies that used the Common Toxicity Criteria version 2.0 and for which a final study publication was available. We extracted from the protocols information pertaining to AE collection and reporting methods and compared it with the methods cited in the article. We also compared the AE data in the trial publication with the AE data submitted by the investigators to CDUS.
                We identified 22 studies meeting the criteria for this review. There was considerable inconsistency between AE collection and reporting methods cited in the protocols versus final publications. AE data in the article and CDUS were not identical. Twenty-seven percent of article high-grade AEs could not be matched to agent-attributable AEs in the CDUS. Twenty-eight percent of CDUS high-grade AEs could not be matched to AEs in the corresponding article. In 14 of 22 articles, the number of high-grade AEs in CDUS differed from the number in the articles by 20% or more.
                Lack of consistency in and reporting of AEs are associated with NCI database and trial publication AE data discrepancy. As of 2005, the International Committee of Medical Journal Editors required investigators to register their trials prior to participant enrollment as a precondition for publishing the trial's findings in member journals.
                To assess the proportion of registered trials with results recently published in journals with high impact factors; to compare the primary outcomes specified in trial registries with those reported in the published articles; and to determine whether primary outcome reporting bias favored significant outcomes.
                MEDLINE via PubMed was searched for reports of randomized controlled trials (RCTs) in 3 medical areas (cardiology, rheumatology, and gastroenterology) indexed in 2008 in the 10 general medical journals and specialty journals with the highest impact factors.
                For each included article, we obtained the trial registration information using a standardized data extraction form.
                Of the 323 included trials, 147 (45.5%) were adequately registered (ie, registered before the end of the trial, with the primary outcome clearly specified). Trial registration was lacking for 89 published reports (27.6%), 45 trials (13.9%) were registered after the completion of the study, 39 (12%) were registered with no or an unclear description of the primary outcome, and 3 (0.9%) were registered after the completion of the study and had an unclear description of the primary outcome. Among articles with trials adequately registered, 31% (46 of 147) showed some evidence of discrepancies between the outcomes registered and the outcomes published. The influence of these discrepancies could be assessed in only half of them and in these statistically significant results were favored in 82.6% (19 of 23).
                Comparison of the primary outcomes of RCTs registered with their subsequent publication indicated that selective outcome reporting is prevalent. To examine the extent to which the Consolidated Standards of Reporting Trials (CONSORT) reporting guidelines improved clinical trials reporting and subject attrition, which may undermine the credibility of published randomized clinical trials (RCTs).
                Published RCTs reported in two major medical journals before and after the CONSORT guidelines were systematically reviewed; one used the CONSORT statement (JAMA) and one did not (NEJM).
                The quality of RCT reporting improved for both journals, but JAMA showed more significant and consistent improvements in all aspects of RCT reporting. Subject attrition was better accounted for after the publication of CONSORT, although the attrition rates for various reasons actually increased. Attrition due to unknown reasons, as a percentage of total attrition, declined dramatically, from 68.7% pre-CONSORT to 13.0% post-CONSORT.
                Attrition of study subjects remains a serious problem in RCTs. Bias from selective attrition can undermine the presumptive scientific advantage of RCTs. The CONSORT guidelines improved RCT reporting when they were implemented but did not substantially improve reported attrition rates. The Consolidated Standards for Reporting of Trials (CONSORT) statement was developed to help improve the quality of reports of randomized controlled trials (RCTs). To date, a paucity of data exists regarding whether it has achieved this goal.
                To determine whether use of the CONSORT statement is associated with improvement in the quality of reports of RCTs.
                Comparative before-and-after evaluation in which reports of RCTs published in 1994 (pre-CONSORT) were compared with RCT reports from the same journals published in 1998 (post-CONSORT). We included 211 reports from BMJ, JAMA, and The Lancet (journals that adopted CONSORT) as well as The New England Journal of Medicine (a journal that did not adopt CONSORT and was used as a comparator).
                Number of CONSORT items included in a report, frequency of unclear reporting of allocation concealment, and overall trial quality score based on the Jadad scale, a 5-point quality assessment instrument.
                Compared with 1994, the number of CONSORT checklist items in reports of RCTs increased in all 4 journals in 1998, and this increase was statistically significant for the 3 adopter journals (pre-CONSORT, 23.4; mean change, 3.7; 95% confidence interval [CI], 2.1-5.3). The frequency of unclear reporting of allocation concealment decreased for each of the 4 journals, and this change was statistically significant for adopters (pre-CONSORT, 61%; mean change, -22%; 95% CI, -38% to -6%). Similarly, 3 of the 4 journals showed an improvement in the quality score for reports of RCTs, and this increase was statistically significant for adopter journals overall (pre-CONSORT, 2.7; mean change, 0.4; 95% CI, 0.1-0.8).
                Use of the CONSORT statement is associated with improvements in the quality of reports of RCTs. Clinical trial registries are in widespread use to promote transparency around trials and their results.
                To describe characteristics of drug trials listed in ClinicalTrials.gov and examine whether the funding source of these trials is associated with favorable published outcomes.
                An observational study of safety and efficacy trials for anticholesteremics, antidepressants, antipsychotics, proton-pump inhibitors, and vasodilators conducted between 2000 and 2006.
                ClinicalTrials.gov, a Web-based registry of clinical trials launched in 1999.
                Publications resulting from the trials for the 5 drug categories of interest were identified, and data were abstracted on the trial record and publication, including timing of registration, elements of the study design, funding source, publication date, and study outcomes. Assessments were based on the primary funding categories of industry, government agencies, and nonprofit or nonfederal organizations.
                Among 546 drug trials, 346 (63%) were primarily funded by industry, 74 (14%) by government sources, and 126 (23%) by nonprofit or nonfederal organizations. Trials funded by industry were more likely to be phase 3 or 4 trials (88.7%; P < 0.001 across groups), to use an active comparator in controlled trials (36.8%; P = 0.010 across groups), to be multicenter (89.0%; P < 0.001 across groups), and to enroll more participants (median sample size, 306 participants; P < 0.001 across groups). Overall, 362 (66.3%) trials had published results. Industry-funded trials reported positive outcomes in 85.4% of publications, compared with 50.0% for government-funded trials and 71.9% for nonprofit or nonfederal organization-funded trials (P < 0.001). Trials funded by nonprofit or nonfederal sources with industry contributions were also more likely to report positive outcomes than those without industry funding (85.0% vs. 61.2%; P = 0.013). Rates of trial publication within 24 months of study completion ranged from 32.4% among industry-funded trials to 56.2% among nonprofit or nonfederal organization-funded trials without industry contributions (P = 0.005 across groups).
                The publication status of a trial could not always be confirmed, which could result in misclassification. Additional information on study protocols and comprehensive trial results were not available to further explore underlying factors for the association between funding source and outcome reporting.
                In this sample of registered drug trials, those funded by industry were less likely to be published within 2 years of study completion and were more likely to report positive outcomes than were trials funded by other sources.
                National Library of Medicine and National Institute of Child Health and Human Development, National Institutes of Health. The "Consolidated Standards of Reporting Trials" (CONSORT) was developed to improve the suboptimal reporting of randomized controlled trials (RCTs). However, little is known about the quality of reporting since this publication. We undertook an observational study to determine the quality of reporting key methodological factors in RCTs since the publication of the CONSORT statement and if a journal policy to promote adherence to the CONSORT checklist was associated with superior reporting. We recorded the reporting of 11 key methodological factors in 105 RCTs from 29 medical journals published subsequent to the CONSORT statement. We examined the quality of reporting in relation to whether a journal was a "CONSORT promoter" as defined by inclusion of the CONSORT checklist in a journal's "information to authors" section or a requirement that authors, manuscript reviewers, or copy editors complete the CONSORT checklist. Multivariate analysis controlled for journal impact factor, study outcome, and time of publication. Six of the 11 methodological factors were reported <50% of the time. The number of methodological factors reported was greater in CONSORT promoters than in journals not promoting CONSORT in both unadjusted (6.0 and 5.1, respectively, p-value = 0.03) and adjusted (6.4 and 4.8 of the 11 methodological factors, respectively, p-value = 0.0001) analyses. While journals that promote CONSORT demonstrate superior reporting of RCTs, persistent inadequacies in reporting remain. Until these inadequacies are resolved health-care providers will remain limited in their ability to make informed inferences about the validity of the studies upon which they base their clinical practice. There has been increasing concern regarding the potential effects of the commercialization of research.
                In order to examine the relationships between funding source, trial outcome and reporting quality, recent issues of five peer-reviewed, high impact factor, general medical journals were hand-searched to identify a sample of 100 randomized controlled trials (20 trials/journal). Relevant data, including funding source (industry/not-for-profit/mixed/not reported) and statistical significance of primary outcome (favouring new treatment/favouring conventional treatment/neutral/unclear), were abstracted. Quality scores were assigned using the Jadad scale and the adequacy of allocation concealment.
                Sixty-six percent of trials received some industry funding. Trial outcome was not associated with funding source (p=.461). There was a preponderance of favourable statistical conclusions among published trials with 67% reporting results that favored a new treatment whereas 6% favoured the conventional treatment. Quality scores were not associated with funding source or trial outcome.
                It is not known whether the absence of significant associations between funding source, trial outcome and reporting quality reflects a true absence of an association or is an artefact of inadequate statistical power, reliance on voluntary disclosure of funding information, a focus on trials recently published in the top medical journals, or some combination thereof. Continued and expanded monitoring of potential conflicts is recommended, particularly in light of new guidelines for disclosure that have been endorsed by the ICMJE. The primary aim of the present study was to identify possible occurrence of selective reporting of the results of clinical trials to the Finnish National Agency for Medicines. Selective reporting may lead to poorly informed action or inaction by regulatory authorities.
                In 1987, 274 clinical drug trials were notified to the Finnish National Agency for Medicines. By December 1993, final reports had been received from 68 of these trials and statements that the trial had been suspended from 24 trials. The sponsors of the non-reported trials were requested to report the outcome. The outcomes, if any, of all reported and non-reported trials were classified as positive, inconclusive or negative.
                The total number of trials with positive, inconclusive or negative outcome were 111, 33 and 44, respectively; the outcomes of 86 trials could not be assessed. Final reports were received from 42/111 (38%) trials with positive, 6/33 (18%) with inconclusive and 9/44 (20%) with negative outcomes.
                Substantial evidence of selective reporting was detected, since trials with positive outcome resulted more often in submission of final report to regulatory authority than those with inconclusive or negative outcomes. Not all clinical trials are published, which may distort the evidence that is available in the literature. We studied the publication rate of a cohort of clinical trials and identified factors associated with publication and nonpublication of results.
                We analysed the protocols of randomized clinical trials of drug interventions submitted to the research ethics committee of University Hospital (Inselspital) Bern, Switzerland from 1988 to 1998. We identified full articles published up to 2006 by searching the Cochrane CENTRAL database (issue 02/2006) and by contacting investigators. We analyzed factors associated with the publication of trials using descriptive statistics and logistic regression models.
                451 study protocols and 375 corresponding articles were analyzed. 233 protocols resulted in at least one publication, a publication rate of 52%. A total of 366 (81%) trials were commercially funded, 47 (10%) had non-commercial funding. 346 trials (77%) were multi-centre studies and 272 of these (79%) were international collaborations. In the adjusted logistic regression model non-commercial funding (Odds Ratio [OR] 2.42, 95% CI 1.14-5.17), multi-centre status (OR 2.09, 95% CI 1.03-4.24), international collaboration (OR 1.87, 95% CI 0.99-3.55) and a sample size above the median of 236 participants (OR 2.04, 95% CI 1.23-3.39) were associated with full publication.
                In this cohort of applications to an ethics committee in Switzerland, only about half of clinical drug trials were published. Large multi-centre trials with non-commercial funding were more likely to be published than other trials, but most trials were funded by industry. The revised Consolidated Standards of Reporting Trials (CONSORT) statement recognizes the importance of including data so that readers are able to judge the reliability or relevance of randomized controlled trial (RCT) findings. However, it is unclear whether journals consistently report the pre-randomization information necessary to assess the general applicability of trial results. The objective of this study was to assess the extent of adherence to pre-randomization data reporting in 4 leading general medicine journals, as recommended by the revised CONSORT statement over a specific time frame. A total of 480 RCTs met the eligibility criteria for review. In 2004, 138 of 246 (56%) articles reported the full CONSORT pre-randomization information, of which 121 (88%) presented this information in diagram form. In 2006, 136 of 234 (58%) reported the full information, of which 127 (93%) presented the information in a diagram. These numbers indicate no improvement in the reporting of pre-randomization information. In conclusion, reporting of the full CONSORT data remains inconsistent. We recommend that journals continue to support the CONSORT statement and ensure that adequate information is provided upon submission before commencing the peer review process. The presentation of clear, precise data will ensure that readers are able to better interpret the applicability of findings. Applicability of randomized controlled clinical trial (RCT) results to 'real world' situations is dependent on the comparability of trial participants to general patient populations. A full disclosure of criteria employed for trial enrollment is necessary for clinicians to assess generalizability. We sought to assess both the impact on generalizability and the disclosure rate of enrollment criteria for 32 major HIV RCTs in the AIDS Clinical Trial Group (ACTG) and Community Programs for Clinical Research on AIDS (CPCRA) trial networks.
                Eligibility criteria were compared in complete protocols to criteria listed in publications from these 32 NIH-funded HIV RCTs. We then applied these criteria to the Women's Interagency HIV Study (WIHS), the largest cohort study of HIV-infected women in the US.
                When applied to WIHS, eligibility criteria from protocols excluded 0-67.6% (median 42%) of WIHS participants (50.6% excluded from ACTG trials). Eligibility criteria in publications excluded 0-62% (median 19.6%) of WIHS (21.2% excluded from ACTG trials). The number of women in WIHS seemingly ineligible for trial participation per enrollment criteria listed in publications averaged only 60% of those actually excluded based on the protocols.
                We found that HIV RCT eligibility criteria excluded a large proportion of a representative cohort of HIV-infected women from trial participation. Furthermore, trial publications are not fully reflective of protocols in terms of disclosing eligibility criteria. Standardization and full disclosure of trial methodology will allow clinicians and researchers to more fully assess the generalizability of findings to their patient populations. Registration of clinical trials has been introduced largely to reduce bias toward statistically significant results in the trial literature. Doubts remain about whether advance registration alone is an adequate measure to reduce selective publication, selective outcome reporting, and biased design. One of the first areas of medicine in which registration was widely adopted was oncology, although the bulk of registered oncology trials remain unpublished. The net influence of registration on the literature remains untested. This study compares the prevalence of favorable results and conclusions among published reports of registered and unregistered randomized controlled trials of new oncology drugs.
                We conducted a cross-sectional study of published original research articles reporting clinical trials evaluating the efficacy of drugs newly approved for antimalignancy indications by the United States Food and Drug Administration (FDA) from 2000 through 2005. Drugs receiving first-time approval for indications in oncology were identified using the FDA web site and Thomson Centerwatch. Relevant trial reports were identified using PubMed and the Cochrane Library. Evidence of advance trial registration was obtained by a search of clinicaltrials.gov, WHO, ISRCTN, NCI-PDQ trial databases and corporate trial registries, as well as articles themselves. Data on blinding, results for primary outcomes, and author conclusions were extracted independently by two coders. Univariate and multivariate logistic regression identified associations between favorable results and conclusions and independent variables including advance registration, study design characteristics, and industry sponsorship.
                Of 137 original research reports from 115 distinct randomized trials assessing 25 newly approved drugs for treating cancer, the 54 publications describing data from trials registered prior to publication were as likely to report statistically significant efficacy results and reach conclusions favoring the test drug (for results, OR = 1.77; 95% CI = 0.87 to 3.61) as reports of trials not registered in advance. In multivariate analysis, reports of prior registered trials were again as likely to favor the test drug (OR = 1.29; 95% CI = 0.54 to 3.08); large sample sizes and surrogate outcome measures were statistically significant predictors of favorable efficacy results at p < 0.05. Subgroup analysis of the main reports from each trial (n = 115) similarly indicated that registered trials were as likely to report results favoring the test drug as trials not registered in advance (OR = 1.11; 95% CI = 0.44 to 2.80), and also that large trials and trials with nonstringent blinding were significantly more likely to report results favoring the test drug.
                Trial registration alone, without a requirement for full reporting of research results, does not appear to reduce a bias toward results and conclusions favoring new drugs in the clinical trials literature. Our findings support the inclusion of full results reporting in trial registers, as well as protocols to allow assessment of whether results have been completely reported. Large clinical trials are the criterion standard for making treatment decisions, and nonpublication of the results of such trials can lead to bias in the literature and contribute to inappropriate medical decisions.
                To determine the rate of full publication of large randomized trials presented at annual meetings of the American Society of Clinical Oncology (ASCO), quantify bias against publishing nonsignificant results, and identify factors associated with time to publication.
                Survey of 510 abstracts from large (sample size, > or =200), phase 3, randomized controlled trials presented at ASCO meetings between 1989 and 1998. Trial results were classified as significant (P< or =.05 for the primary outcome measure) or nonsignificant (P>.05 or not reported), and the type of presentation and sponsorship were identified. Subsequent full publication was identified using a search of MEDLINE and EMBASE, completed November 1, 2001; the search was updated in November 2002, using the Cochrane Register of Controlled Trials. Authors were contacted if the searches did not find evidence of publication.
                Publication rate at 5 years; time from presentation to full publication.
                Of 510 randomized trials, 26% were not published in full within 5 years after presentation at the meeting. Eighty-one percent of the studies with significant results had been published by this time compared with 68% of the studies with nonsignificant results (P<.001). Studies with oral or plenary presentation were published sooner than those not presented (P =.002), and studies with pharmaceutical sponsorship were published sooner than studies with cooperative group sponsorship or studies for which sponsorship was not specified (P =.02). These factors remained significant in a multivariable model. The most frequent reason cited by authors for not publishing was lack of time, funds, or other resources.
                A substantial number of large phase 3 trials presented at an international oncology meeting remain unpublished 5 years after presentation. Bias against publishing nonsignificant results is a problem even for large randomized trials. Nonpublication breaks the contract that investigators make with trial participants, funding agencies, and ethics boards. CONSORT (Consolidated Standards for Reporting Trials) guidelines were constructed to ensure optimal reporting quality of randomized controlled trials (RCTs).
                To determine the effect of the adoption of CONSORT on the reporting quality of RCTs, we performed a systematic evaluation of RCTs published in two dermatology journals pre- and post-CONSORT adoption.
                The journals selected for the study were the Journal of the American Academy of Dermatology and the British Journal of Dermatology. We selected RCTs published in 1997 and 2006 using both Medline and hand searching. The following critical CONSORT criteria were recorded: sample size, type of disease studied, type of control, single-centre or multicentre study, type of funding, blinding, methods and type of randomization, definition of a primary endpoint, justification for sample size selection and power calculation, population for analysis, and adequacy of group comparison. A multivariable analysis was conducted to determine factors associated with optimal reporting quality.
                In total, 98 studies were included. Improvement in reporting quality was evident for the specification of the randomization method (20% in 1997 vs. 45% in 2006, P < 0.01) and for the justification of sample size (22% in 1997 vs. 43% in 2006, P = 0.027). The percentage of studies with optimal reporting quality increased from 11% in 1997 to 28% in 2006 (P = 0.03). Factors significantly associated with a good methodological quality were pharmaceutical industry funding and publication in 2006 vs. 1997.
                There is a need to improve the reporting quality of RCTs published in dermatology journals.
Discrepancies between protocols or trial registry entries and trial reports were common, although reasons for these were not discussed in the reports. Full transparency will be possible only when protocols are made publicly available or the quality and extent of information included in trial registries is improved, and trialists explain substantial changes in their reports.