Comparison of registered and published primary outcomes in randomized controlled trials. Role of a research ethics committee in follow-up and publication of results. Outcome reporting among drug trials registered in ClinicalTrials.gov. Outcome reporting in industry-sponsored trials of gabapentin for off-label use. Reporting the study populations of clinical trials. Clear transmission or static on the line? Selective reporting in clinical trials: analysis of trial protocols accepted by The Lancet. Clinical research projects at a German medical faculty: follow-up from ethical approval to publication and citation by others. Publication and non-publication of clinical trials: longitudinal study of applications submitted to a research ethics committee. Empirical evidence for selective reporting of outcomes in randomized trials: comparison of protocols to published articles. Adverse event reporting in publications compared with sponsor database for cancer clinical trials. Investigation of within-study selective reporting in clinical research: follow-up of applications submitted to a local research ethics committee. Reporting of sample size calculation in randomised controlled trials: review. Bad reporting does not mean bad methods for randomised trials: observational study of randomised controlled trials performed by the Radiation Therapy Oncology Group. Outcome reporting bias in randomized trials funded by the Canadian Institutes of Health Research. Eligibility criteria for HIV clinical trials and generalizability of results: the gap between published reports and study protocols. Undisclosed changes in outcomes in randomized controlled trials: an observational study.
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. Follow-up of clinical trials is a commitment rarely fulfilled by research ethics committees (RECs). We assessed the output of clinical trials submitted in 1997 to our REC, and talked to principal investigators, sponsors, contract research organisations, or a combination of these. During 1997, our REC reviewed 166 clinical trials, and approved 158. The recruitment rate was lower than expected in 45% (64/143) of all initiated clinical trials; 64% (92/143) were finished in accordance with protocol. 3 years after, the results of only 21% (26/123) of finished clinical trials were published in peer-reviewed journals, rising to 31% (38/123) if in-press articles were included. RECs should devote more effort and resources to assess public dissemination of results of clinical trials. 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. There is good evidence of selective outcome reporting in published reports of randomized trials.
                We examined reporting practices for trials of gabapentin funded by Pfizer and Warner-Lambert's subsidiary, Parke-Davis (hereafter referred to as Pfizer and Parke-Davis) for off-label indications (prophylaxis against migraine and treatment of bipolar disorders, neuropathic pain, and nociceptive pain), comparing internal company documents with published reports.
                We identified 20 clinical trials for which internal documents were available from Pfizer and Parke-Davis; of these trials, 12 were reported in publications. For 8 of the 12 reported trials, the primary outcome defined in the published report differed from that described in the protocol. Sources of disagreement included the introduction of a new primary outcome (in the case of 6 trials), failure to distinguish between primary and secondary outcomes (2 trials), relegation of primary outcomes to secondary outcomes (2 trials), and failure to report one or more protocol-defined primary outcomes (5 trials). Trials that presented findings that were not significant (P > or = 0.05) for the protocol-defined primary outcome in the internal documents either were not reported in full or were reported with a changed primary outcome. The primary outcome was changed in the case of 5 of 8 published trials for which statistically significant differences favoring gabapentin were reported. Of the 21 primary outcomes described in the protocols of the published trials, 6 were not reported at all and 4 were reported as secondary outcomes. Of 28 primary outcomes described in the published reports, 12 were newly introduced.
                We identified selective outcome reporting for trials of off-label use of gabapentin. This practice threatens the validity of evidence for the effectiveness of off-label interventions.
                2009 Massachusetts Medical Society In contrast to attempts that have been made to measure the clarity of reporting of the methods of clinical trials in journal articles, we report here an attempt to measure the accuracy of methods reporting. We focus in this article on eligibility criteria as a test case for the reporting of clinical trial methods. We examined the reporting of eligibility criteria in the protocol, methods paper (if applicable), journal article, and Clinical Alert for articles appearing in print between January 1988 and September 1994 for which a Clinical Alert had been issued. Eligibility criteria were further classified into five categories in order to examine the content of information loss, if any. On average, 82% of protocol eligibility criteria were reported in methods papers. Journal articles and Clinical Alerts fared somewhat worse: 63% of criteria were reported in journal articles, 19% in Clinical Alerts. In all three categories of medical communication, the reporting of criteria that defined the study disease tended to be complete; reporting of criteria relating to trial precision, patient safety, legal and ethical concerns, and administrative considerations, was not complete. We found that criteria for clinical trial eligibility are frequently under-reported in medical communications. Moreover, some of the criteria omitted are of considerable clinical importance. We suggest that in the design phase of clinical trials, proposed eligibility criteria be scrutinized closely. Those criteria that survive this scrutiny and that have clinical import must be reported upon fully and accurately when communicating trial results. nan Only data of published study results are available to the scientific community for further use such as informing future research and synthesis of available evidence. If study results are reported selectively, reporting bias and distortion of summarised estimates of effect or harm of treatments can occur. The publication and citation of results of clinical research conducted in Germany was studied.
                The protocols of clinical research projects submitted to the research ethics committee of the University of Freiburg (Germany) in 2000 were analysed. Published full articles in several databases were searched and investigators contacted. Data on study and publication characteristics were extracted from protocols and corresponding publications.
                299 study protocols were included. The most frequent study design was randomised controlled trial (141; 47%), followed by uncontrolled studies (61; 20%), laboratory studies (30; 10%) and non-randomised studies (29; 10%). 182 (61%) were multicentre studies including 97 (53%) international collaborations. 152 of 299 (51%) had commercial (co-)funding and 46 (15%) non-commercial funding. 109 of the 225 completed protocols corresponded to at least one full publication (total 210 articles); the publication rate was 48%. 168 of 210 identified publications (80%) were cited in articles indexed in the ISI Web of Science. The median was 11 citations per publication (range 0-1151).
                Results of German clinical research projects conducted are largely underreported. Barriers to successful publication need to be identified and appropriate measures taken. Close monitoring of projects until publication and adequate support provided to investigators may help remedy the prevailing underreporting of research. 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. 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. 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. Within-study selective reporting is widely believed to exist, although to date there have been no empirical studies to assess the extent of the problem in clinical research. The present study aimed to examine this process.
                We undertook a pilot study, involving a single local research ethics committee (LREC), in which we compared the outcomes, analysis and sample size proposed in the original approved study protocol with the results presented in the subsequent study report.
                We received 41 (73%) replies from lead researchers of 56 projects, which were a complete cohort of clinical research applications approved in a particular time period by the LREC. Fifteen of these projects, which were completed and published at the time of our study, were further investigated. Only six (40%) stated which outcome variables were of primary interest and four (67%) of these showed consistency in the reports. Eight (53%) of the 15 studies mentioned an analysis plan. However, seven (88%) of these eight studies did not follow their prescribed analysis plan: the analysis of outcome variables or associations between certain variables were found to be missing from the report.
                Our pilot study has shown that within-study selective reporting may be examined qualitatively by comparing the study report with the study protocol. Our results suggest that it might well be substantial; however, the bias can only be broadly identified as protocols are not sufficiently precise. To assess quality of reporting of sample size calculation, ascertain accuracy of calculations, and determine the relevance of assumptions made when calculating sample size in randomised controlled trials.
                Review.
                We searched MEDLINE for all primary reports of two arm parallel group randomised controlled trials of superiority with a single primary outcome published in six high impact factor general medical journals between 1 January 2005 and 31 December 2006. All extra material related to design of trials (other articles, online material, online trial registration) was systematically assessed. Data extracted by use of a standardised form included parameters required for sample size calculation and corresponding data reported in results sections of articles. We checked completeness of reporting of the sample size calculation, systematically replicated the sample size calculation to assess its accuracy, then quantified discrepancies between a priori hypothesised parameters necessary for calculation and a posteriori estimates.
                Of the 215 selected articles, 10 (5%) did not report any sample size calculation and 92 (43%) did not report all the required parameters. The difference between the sample size reported in the article and the replicated sample size calculation was greater than 10% in 47 (30%) of the 157 reports that gave enough data to recalculate the sample size. The difference between the assumptions for the control group and the observed data was greater than 30% in 31% (n=45) of articles and greater than 50% in 17% (n=24). Only 73 trials (34%) reported all data required to calculate the sample size, had an accurate calculation, and used accurate assumptions for the control group.
                Sample size calculation is still inadequately reported, often erroneous, and based on assumptions that are frequently inaccurate. Such a situation raises questions about how sample size is calculated in randomised controlled trials. To determine whether poor reporting of methods in randomised controlled trials reflects on poor methods.
                Observational study.
                Reports of randomised controlled trials conducted by the Radiation Therapy Oncology Group since its establishment in 1968.
                The Radiation Therapy Oncology Group. Outcome measures Content of reports compared with the design features described in the protocols for all randomised controlled trials.
                The methodological quality of 56 randomised controlled trials was better than reported. Adequate allocation concealment was achieved in all trials but reported in only 42% of papers. An intention to treat analysis was done in 83% of trials but reported in only 69% of papers. The sample size calculation was performed in 76% of the studies, but reported in only 16% of papers. End points were clearly defined and alpha and beta errors were prespecified in 76% and 74% of the trials, respectively, but only reported in 10% of the papers. The one exception was the description of drop outs, where the frequency of reporting was similar to that contained in the original statistical files of the Radiation Therapy Oncology Group.
                The reporting of methodological aspects of randomised controlled trials does not necessarily reflect the conduct of the trial. Reviewing research protocols and contacting trialists for more information may improve quality assessment. The reporting of outcomes within published randomized trials has previously been shown to be incomplete, biased and inconsistent with study protocols. We sought to determine whether outcome reporting bias would be present in a cohort of government-funded trials subjected to rigorous peer review.
                We compared protocols for randomized trials approved for funding by the Canadian Institutes of Health Research (formerly the Medical Research Council of Canada) from 1990 to 1998 with subsequent reports of the trials identified in journal publications. Characteristics of reported and unreported outcomes were recorded from the protocols and publications. Incompletely reported outcomes were defined as those with insufficient data provided in publications for inclusion in meta-analyses. An overall odds ratio measuring the association between completeness of reporting and statistical significance was calculated stratified by trial. Finally, primary outcomes specified in trial protocols were compared with those reported in publications.
                We identified 48 trials with 68 publications and 1402 outcomes. The median number of participants per trial was 299, and 44% of the trials were published in general medical journals. A median of 31% (10th-90th percentile range 5%-67%) of outcomes measured to assess the efficacy of an intervention (efficacy outcomes) and 59% (0%-100%) of those measured to assess the harm of an intervention (harm outcomes) per trial were incompletely reported. Statistically significant efficacy outcomes had a higher odds than nonsignificant efficacy outcomes of being fully reported (odds ratio 2.7; 95% confidence interval 1.5-5.0). Primary outcomes differed between protocols and publications for 40% of the trials.
                Selective reporting of outcomes frequently occurs in publications of high-quality government-funded trials. 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. 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.
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.