Cumulative meta-analysis of clinical trials builds evidence for exemplary medical care. Association of funding and conclusions in randomized drug trials: a reflection of treatment effect or adverse events? Comparison of registered and published primary outcomes in randomized controlled trials. Source of funding and outcome of clinical trials. A cohort study of summary reports of controlled trials. Publication and non-publication of clinical trials: longitudinal study of applications submitted to a research ethics committee. Effect of a US National Institutes of Health programme of clinical trials on public health and costs. Outcome reporting among drug trials registered in ClinicalTrials.gov. Cumulative meta-analysis of therapeutic trials for myocardial infarction. Funding source, trial outcome and reporting quality: are they related? Results of a pilot study. Factors associated with failure to publish large randomized trials presented at an oncology meeting. Clinical research projects at a German medical faculty: follow-up from ethical approval to publication and citation by others. Secular changes in the quality of published randomized clinical trials in rheumatology. Abstracts of trials presented at the Vth World Congress of Psychiatry (Mexico, 1971): a cohort study. Quality of reporting of randomized, controlled trials in cerebral palsy. Empirical evidence for selective reporting of outcomes in randomized trials: comparison of protocols to published articles. Association of industry sponsorship to published outcomes in gastrointestinal clinical research. An educational video to increase clinical trials enrollment among lung cancer patients. Quality assessment of reports on clinical trials in the Journal of Hepatology. Publication bias and meta-analyses: a practical example. Does quality of reports of randomised trials affect estimates of intervention efficacy reported in meta-analyses? Reported outcomes in major cardiovascular clinical trials funded by for-profit and not-for-profit organizations: 2000-2005. Reporting of randomized controlled trials in Hodgkin lymphoma in biomedical journals. Examination of the analytic quality of behavioral health randomized clinical trials. Evidence of improving quality of reporting of randomized controlled trials in subfertility. Industry sponsorship and authorship of clinical trials over 20 years. How study design affects outcomes in comparisons of therapy. I: Medical. Treatment success in cancer: new cancer treatment successes identified in phase 3 randomized controlled trials conducted by the National Cancer Institute-sponsored cooperative oncology groups, 1955 to 2006. Full publication of trials initially reported as abstracts in the Australian and New Zealand Journal of Medicine 1980-2000. Issues that may determine the outcome of antipsychotic trials: industry sponsorship and extrapyramidal side effect. Impact of study quality on outcome in placebo-controlled trials of homeopathy. Is the future for clinical trials internet-based? A cluster randomized clinical trial. Conducting a randomized clinical trial of an psychological intervention for parents/caregivers of children with cancer shortly after diagnosis. Abstracts of randomized controlled trials presented at the society for pediatric research meeting: an example of publication bias. Analysis of the quality of reporting of randomized controlled trials in acute and chronic myeloid leukemia, and myelodysplastic syndromes as governed by the CONSORT statement. [The identification and description of clinical trials published in Spanish journals of general and internal medicine during the period of 1971-1995]. Outcome reporting bias in randomized trials funded by the Canadian Institutes of Health Research. Influence of drug company authorship and sponsorship on drug trial outcomes. A randomized controlled trial evaluating the impact of knowledge translation and exchange strategies.
Cumulative meta-analysis of clinical trials (a Bayesian interpretation for accumulating evidence) will profoundly affect medical care by summarizing evidence in the assessment of technology innovations. Application of the technique to the randomized control trials (RCTs) of streptokinase treatment of acute myocardial infarction, reduction of peri-operative mortality by antibiotic prophylaxis, and prevention of death from bleeding peptic ulcers has revealed efficacy years before it was suspected by any other means. Arrangement of the trials according to event rate in the controls, effect sizes, quality of the trials or according to covariables of interest has supplied unique information. If carried out prospectively the technique supplies invaluable information regarding indications for another trial, the number of patients necessary to determine the validity of past trends, and the type of patients who might be benefitted. Careful examination in a cumulative manner of the prior trials can reduce the need for future large trials. Previous studies indicate that industry-sponsored trials tend to draw proindustry conclusions.
                To explore whether the association between funding and conclusions in randomized drug trials reflects treatment effects or adverse events.
                Observational study of 370 randomized drug trials included in meta-analyses from Cochrane reviews selected from the Cochrane Library, May 2001. From a random sample of 167 Cochrane reviews, 25 contained eligible meta-analyses (assessed a binary outcome; pooled at least 5 full-paper trials of which at least 1 reported adequate and 1 reported inadequate allocation concealment). The primary binary outcome from each meta-analysis was considered the primary outcome for all trials included in each meta-analysis. The association between funding and conclusions was analyzed by logistic regression with adjustment for treatment effect, adverse events, and additional confounding factors (methodological quality, control intervention, sample size, publication year, and place of publication).
                Conclusions in trials, classified into whether the experimental drug was recommended as the treatment of choice or not.
                The experimental drug was recommended as treatment of choice in 16% of trials funded by nonprofit organizations, 30% of trials not reporting funding, 35% of trials funded by both nonprofit and for-profit organizations, and 51% of trials funded by for-profit organizations (P<.001; chi2 test). Logistic regression analyses indicated that funding, treatment effect, and double blinding were the only significant predictors of conclusions. Adjusted analyses showed that trials funded by for-profit organizations were significantly more likely to recommend the experimental drug as treatment of choice (odds ratio, 5.3; 95% confidence interval, 2.0-14.4) compared with trials funded by nonprofit organizations. This association did not appear to reflect treatment effect or adverse events.
                Conclusions in trials funded by for-profit organizations may be more positive due to biased interpretation of trial results. Readers should carefully evaluate whether conclusions in randomized trials are supported by data. 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. Because of recent concerns about conflicts of interest and published research, the author analyzed 107 controlled clinical trials. Studies were classified as favoring either a new therapy or a traditional therapy, and as being supported by a pharmaceutical manufacturer or as being generally supported. Seventy-one per cent of the trials favored new therapies; 43% of these were funded by pharmaceutical firms. Of the 31 trials favoring traditional therapy, only four (13%) were supported by a pharmaceutical firm. There was a statistically significant association between the source of funding and the outcome of the study (p = 0.002). Few trials supported by pharmaceutical manufacturers favored traditional therapy; some reasons for this finding may include selection of drugs likely to be proven efficacious, Type II errors (false-negative studies), and fear of discontinuation of funding should such studies be submitted. Important clinical information may be lost if negative studies are not published. Substantial numbers of clinical trials continue to be reported only in summary reports that present insufficient methodological details to permit informed judgments about the likely validity of the conclusions. Using a cohort of 176 controlled trials reported in summary form, we tested the hypotheses that they would be more likely to be followed by full reports if, on the basis of the information provided in the summary report, (1) the trial was judged to be methodologically sound, (2) the results favored the test treatment, and (3) the sample size was relatively large. The results of univariate and multivariate analyses provided support for only the third of these hypotheses. Investigators, as well as those who fund and sanction the conduct of clinical research, should make greater efforts to ensure that clinical trials are reported properly. 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. Few attempts have been made to estimate the public return on investment in medical research. The total costs and benefits to society of a clinical trial, the final step in testing an intervention, can be estimated by evaluating the effect of trial results on medical care and health.
                All phase III randomised trials funded by the US National Institute of Neurological Disorders and Stroke before Jan 1, 2000, were included. Pertinent publications on use, cost to society, and health effects for each studied intervention were identified by systematic review, supplemented with data from other public and proprietary sources. Regardless of whether a trial was positive or negative, information on use of tested therapies was integrated with published per-use data on costs and health effect (converted to 2004 US dollars) to generate 10-year projections for the US population.
                28 trials with a total cost of 335 million dollars were included. Six trials (21%) resulted in measurable improvements in health, and four (14%) resulted in cost savings to society. At 10 years, the programme of trials resulted in an estimated additional 470,000 quality-adjusted life years at a total cost of 3.6 billion dollars (including costs of all trials and additional health-care and other expenditures). Valuing a quality-adjusted life year at per-head gross domestic product, the projected net benefit to society at 10-years was 15.2 billion dollars. 95% CIs did not include a net loss at 10 years.
                For this institute, the public return on investment in clinical trials has been substantial. Although results led to increases in health-care expenditures, health gains were large and valuable. 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 large volume of published randomized, controlled trials has led to a need for meta-analyses to track therapeutic advances. Performing a new meta-analysis whenever the results of a new trial of a particular therapy are published permits the study of trends in efficacy and makes it possible to determine when a new treatment appears to be significantly effective or deleterious. We describe the use of such a procedure, cumulative meta-analysis, to assess therapeutic trials among patients with myocardial infarction.
                We performed cumulative meta-analyses of clinical trials that evaluated 15 treatments and preventive measures for acute myocardial infarction.
                An example of this method is its application to the use of intravenous streptokinase as thrombolytic therapy for acute infarction. Thirty-three trials evaluating this therapy were performed between 1959 and 1988. We found that a consistent, statistically significant reduction in total mortality (odds ratios, 0.74; 95 percent confidence interval, 0.59 to 0.92) was achieved in 1973, after only eight trials involving 2432 patients had been completed. The results of the 25 subsequent trials, which enrolled an additional 34,542 patients through 1988, had little or no effect on the odds ratio establishing efficacy, but simply narrowed the 95 percent confidence interval. In particular, two very large trials, the Gruppo Italiano per lo Studio della Streptochinasi nell'Infarto Miocardico trial in 1986 (11,712 patients) and the Second International Study of Infarct Survival trial in 1988 (17,187 patients) did not modify the already established evidence of efficacy. We used a similar approach to study the accumulating evidence of efficacy (or lack of efficacy) of 14 other therapies and preventive measures for myocardial infarction.
                Cumulative meta-analysis of therapeutic trials facilitates the determination of clinical efficacy and harm and may be helpful in tracking trials, planning future trials, and making clinical recommendations for therapy. 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. 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. 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. To assess the quality of published randomized clinical trials (RCTs) in rheumatology and to determine whether there has been improvement in quality between 2 time periods, 1987-1988 and 1997-1998.
                Using MEDLINE and a hand search of selected rheumatology journals, we identified RCTs of adult rheumatic diseases published in English in 1987-1988 or 1997-1998. We examined trial quality with an expanded version of the Jadad scale, which assesses the adequacy of reported random sequence generation, allocation concealment, blinding, and analysis. All trials were read by 1 reviewer, with prior standardization using a random sample read by 2 reviewers. We also evaluated "high"- versus "low"-impact journals based on citation index.
                Two hundred forty RCTs (1987-1988 119 RCTs, 1997-1998 121 RCTs) were assessed. Results showed improvement in the quality of the trials, but the rates of reported random sequence generation, allocation concealment, power, and intent-to-treat analyses were persistently low. Low rates of reports of random sequence generation, allocation concealment, and intent-to-treat analyses were present even in the high-impact journals.
                There has been improvement in the quality of reporting of RCTs in rheumatology between 1987-1988 and 1997-1998. However, methodologic problems such as lack of allocation concealment, inadequate random sequence generation, lack of reporting of power, and lack of intent-to-treat analyses remain common. Many of these problems are established sources of bias in RCTs and are easily rectifiable. Systematic reviews should identify all relevant trials in order to minimize the potential for bias and the play of chance in their results. Other specialities have shown that conference proceedings are a rich source of trials, but many of these trials are never fully published.
                All clinical trials presented at a single conference (Vth World Congress of Psychiatry, Mexico, 1971) were identified by hand searching. Full publications of these abstracts were then sought on five databases by searching for the authors or relevant key words.
                Full publications were found for 46% of the abstracts. The odds of publication decreased for abstracts that were from a non-Anglophone country or that failed to mention randomization.
                Anyone wishing to undertake a systematic review of a mental-health care topic should search relevant conference proceedings for trials. In conducting reviews on the effectiveness of physiotherapy interventions on children with cerebral palsy, the assessment of trials can be hampered by problems in reporting. Therefore, we set out to evaluate trial reporting by using the Consolidated Standards of Reporting Trials (CONSORT) statement recommendations.
                Randomized, controlled trials published in 1990 or later were identified in literature searches for reviews on the effectiveness of physiotherapy interventions on children with cerebral palsy. Two independent reviewers evaluated the trial reporting by using a modified 33-item Consolidated Standards of Reporting Trials checklist.
                We identified 15 randomized, controlled trials. Almost half (48%) of the applicable items were reported adequately. Inadequate reporting was found in the following items: outcome measures, sample-size determination, details of the sequence generation, allocation concealment and implementation of the randomization, success of assessor blinding, recruitment and follow-up dates, intention-to-treat analysis, precision of the effect size, co-interventions, and adverse events.
                Only a small number of sufficiently reported trials were found. Because nearly all items had been described in at least 1 article, high-quality reporting seems feasible. Assessment of trials depends on appropriate reporting, and poor reporting jeopardizes judgments on the clinical implications. Authors of randomized, controlled trials are encouraged to follow the Consolidated Standards of Reporting Trials criteria. There is a clear need to improve the quality of reporting of trials in this field. 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. Recent years have seen an increase in industry sponsorship of clinical trials throughout medicine. We conducted a study to evaluate the association of industry sponsorship to published outcomes in gastrointestinal (GI) clinical research. Our aims were (1) to evaluate the trends in the source of funding for GI clinical research during the period from 1992 to 2002-2003, (2) to determine whether the source of study funding predicted the likelihood that a study would publish results that favor the drug or device being tested, and (3) to determine whether differences exist in the methodologic quality of the investigational study methods used in studies funded by private industry versus other sources.
                We selected all clinical studies evaluating a drug or device from 4 prominent GI journals (Gastroenterology, The American Journal of Gastroenterology, Hepatology, and Gastrointestinal Endoscopy). All studies were abstracted by using a standardized data abstraction form. We evaluated the trends in funding source for studies published during the years 1992, 2002, and 2003. All selected studies were scored for methodologic quality by using a previously validated scoring system. The percentage of studies that reported outcomes that favored the device or drug being tested against the standard therapy or placebo was determined for each funding source. A funnel plot was constructed to assess for the presence of negative publication bias.
                A total of 6326 studies were reviewed. For the 1992 trend data, 1860 studies were reviewed, and 135 were selected for inclusion in the study. Ninety-five studies were studies involving the investigation of drugs, and 40 studies involved the testing of a device. For the 2002-2003 data 4466 studies were reviewed, and 315 were selected for inclusion in the study. Two hundred twenty-two studies were clinical trials involving the investigation of drugs, and 93 were clinical trials involving devices. In comparing 1992 to 2002, the percentage of studies funded by industry sources more than doubled from 10% to greater than 28% of the total studies assessed. There was an associated decline in the proportion of studies with funding from non-industry sources during this period (62% to less than 48%). The percentage of studies that did not disclose a funding source fell modestly from 28% to 24%. We found that 86% of studies funded by private industry reported a result favorable to the study drug or device, and 83% of studies funded by academic sources reported a result favorable to the study drug or device (P=.572). On average, studies funded by private industry had a higher methodology score than studies funded by traditional academic sources (75 of 100 vs 65 of 100; P=.005). Analysis of the funnel plot did not reveal evidence of bias against the publication of small studies with insignificant results.
                The proportion of research funded by industry has more than doubled during the last decade and currently comprises almost half of the funding for GI clinical research. Industry-sponsored studies are, on average, of superior methodologic quality to studies funded by other sources. Industry-sponsored studies in leading GI journals were no more likely than other studies to publish results that favored the study sponsor, although an extremely high percentage of all studies in these journals reported positive results. There has been only a modest decline in studies not acknowledging a funding source. Only 3 to 5% of new adult cancer patients participate in clinical trials nationwide. The lack of knowledge and awareness about clinical trials is a significant barrier to clinical trials participation. A randomized trial was conducted to test the effect of an educational video on positively changing patients' knowledge and attitudes regarding clinical trials and thereby increasing enrollment rates.
                Lung cancer patients were randomized to viewing either an 18-minute video about clinical trials before first clinic appointment or to standard care. Participants completed a baseline and 2-week postintervention survey to assess their knowledge and attitudes toward trials participation. Fisher's exact test tests, t tests, and regression were used to compare patient characteristics and outcomes between arms.
                Of 145 subjects randomized, 126 (63/arm) satisfied all inclusion criteria and were included in the analysis. A linear regression showed that the video intervention was significantly associated with patients' self-assessed likelihood to enroll score measured at 2-week follow-up (p = 0.019). Although statistically insignificant, enrollment rates were found to be higher in the intervention arm for therapeutic trials alone (17.5% versus 11.1%) and for therapeutic and nontherapeutic trials combined (25.4% versus 15.9%).
                The brief educational video seems to be effective in positively changing lung cancer patients' attitudes about participation in clinical trials. Higher enrollment rates were also observed in the intervention group but the differences did not reach statistical significance. These findings suggest a potential impact of the educational video on clinical trial enrollment; however, larger studies are needed to confirm these findings. Electronic searches on databases for randomised clinical trials and controlled clinical trials do not identify as many trials as handsearches, and trial reporting may be flawed. The aims were to identify all fully reported randomised clinical trials in the Journal of Hepatology and to make a qualitative assessment of the reporting.
                The publications were identified by systematically handsearching the full text of the journal and searching MEDLINE. Central dimensions of trial quality were used to assess the reporting quality of the trials.
                Randomised clinical trials represented 8.4% of the original articles (171/2028). Ten original articles (0.5%) could not be classified. A search on MEDLINE identified 81.3% of the randomised clinical trials, i.e., 139 out of the 171 identified by the handsearch. A total of 166 randomised clinical trials could be quality assessed. Forty-seven (28.3%) of them reported adequate generation of allocation sequence; 22 (13.3%) adequate allocation concealment; 95 (57.2%) allowed intention-to-treat analysis with only a few losses to follow-up; 50 (30.1%) were double-blind; 33 (19.9%) reported sample-size calculations; 13 trials (7.8%) employed the crossover design; and the median number of subjects per intervention arm in parallel group trials was 19 subjects (interquartile range: 11-31; range: 5-519). The quality of reporting was significantly better in regular issue articles than in supplement articles.
                Many important randomised clinical trials are published in the Journal of Hepatology, but there seems to be ample room for improvement of quality of reporting. Publication bias is widely appreciated, but considerable time and effort are needed to locate and obtain data from unpublished randomized controlled trials (RCTs), those published in non-English language journals or those reported in the gray literature; for this publication, we will call this collection of trials the "gray+literature." However, excluding such trials from systematic reviews could introduce bias and give rise to misleading conclusions.
                We aimed to explore and quantify the impact of inclusion of gray+ literature on the results of all completed individual patient data (IPD) reviews coordinated by our group (13 meta-analyses). For each IPD review, results were calculated for RCTs fully published in English language journals and RCTs fully published in English language journals and the gray+literature.
                The IPD meta-analyses based only on RCTs that were fully published in English language journals tended to give more favorable results than those that included RCTs from the gray+literature. Although in most cases the addition of gray+data gave less encouraging results, moving the estimated treatment effect toward a null result, the direction of effect was not always predictable.
                We recommend that all systematic reviews should at least attempt to identify trials reported in the gray+literature and, where possible, obtain data from them. Few meta-analyses of randomised trials assess the quality of the studies included. Yet there is increasing evidence that trial quality can affect estimates of intervention efficacy. We investigated whether different methods of quality assessment provide different estimates of intervention efficacy evaluated in randomised controlled trials (RCTs).
                We randomly selected 11 meta-analyses that involved 127 RCTs on the efficacy of interventions used for circulatory and digestive diseases, mental health, and pregnancy and childbirth. We replicated all the meta-analyses using published data from the primary studies. The quality of reporting of all 127 clinical trials was assessed by means of component and scale approaches. To explore the effects of quality on the quantitative results, we examined the effects of different methods of incorporating quality scores (sensitivity analysis and quality weights) on the results of the meta-analyses.
                The quality of trials was low. Masked assessments provided significantly higher scores than unmasked assessments (mean 2.74 [SD 1.10] vs 2.55 [1.20]). Low-quality trials (score < or = 2), compared with high-quality trials (score > 2), were associated with an increased estimate of benefit of 34% (ratio of odds ratios [ROR] 0.66 [95% CI 0.52-0.83]). Trials that used inadequate allocation concealment, compared with those that used adequate methods, were also associated with an increased estimate of benefit (37%; ROR=0.63 [0.45-0.88]). The average treatment benefit was 39% (odds ratio [OR] 0.61 [0.57-0.65]) for all trials, 52% (OR 0.48 [0.43-0.54]) for low-quality trials, and 29% (OR 0.71 [0.65-0.77]) for high-quality trials. Use of all the trial scores as quality weights reduced the effects to 35% (OR 0.65 [0.59-0.71]) and resulted in the least statistical heterogeneity.
                Studies of low methodological quality in which the estimate of quality is incorporated into the meta-analyses can alter the interpretation of the benefit of intervention, whether a scale or component approach is used in the assessment of trial quality. In surveys based on data available prior to 2000, clinical trials funded by for-profit organizations appeared more likely to report positive findings than those funded by not-for-profit organizations. Whether this situation has changed over the past 5 years or whether similar effects are present among jointly funded trials is unknown.
                To determine in contemporary randomized cardiovascular trials the association between funding source and the likelihood of reporting positive findings.
                We reviewed 324 consecutive superiority trials of cardiovascular medicine published between January 1, 2000, and July 30, 2005, in JAMA, The Lancet, and the New England Journal of Medicine.
                The proportion of trials favoring newer treatments over the standard of care was evaluated by funding source.
                Of the 324 superiority trials, 21 cited no funding source. Of the 104 trials funded solely by not-for-profit organizations, 51 (49%) reported evidence significantly favoring newer treatments over the standard of care, whereas 53 (51%) did not (P = .80). By contrast, 92 (67.2%) of 137 trials funded solely by for-profit organizations favored newer treatments over standard of care (P<.001). Among 62 jointly funded trials, 35 (56.5%), an intermediate proportion, favored newer treatments. For 205 randomized trials evaluating drugs, the proportions favoring newer treatments were 39.5%, not-for-profit; 54.4%, jointly funded; and 65.5%, for-profit trials (P for trend across groups = .002). For the 39 randomized trials evaluating cardiovascular devices, the proportions favoring newer treatments were 50.0%, not-for-profit; 69.2%, jointly funded; and 82.4%, for-profit trials (P for trend across groups = .07). Regardless of funding source, trials using surrogate end points, such as quantitative angiography, intravascular ultrasound, plasma biomarkers, and functional measures were more likely to report positive findings (67%) than trials using clinical end points (54.1%; P = .02).
                Recent cardiovascular trials funded by for-profit organizations are more likely to report positive findings than trials funded by not-for-profit organizations, as are trials using surrogate rather than clinical end points. Trials jointly funded by not-for-profit and for-profit organizations appear to report positive findings at a rate approximately midway between rates observed in trials supported solely by one or the other of these entities. Randomized controlled trials (RCTs) are the best tool to evaluate the effectiveness of clinical interventions. The Consolidated Standards for Reporting Trials (CONSORT) statement was introduced in 1996 to improve reporting of RCTs. We aimed to determine the extent of ambiguity and reporting quality as assessed by adherence to the CONSORT statement in published reports of RCTs involving patients with Hodgkin lymphoma from 1966 through 2002.
                We analyzed 242 published full-text reports of RCTs in patients with Hodgkin lymphoma. Quality of reporting was assessed using a 14-item questionnaire based on the CONSORT checklist. Reporting was studied in two pre-CONSORT periods (1966-1988 and 1989-1995) and one post-CONSORT period (1996-2002).
                Only six of the 14 items were addressed in 75% or more of the studies in all three time periods. Most items that are necessary to assess the methodologic quality of a study were reported by fewer than 20% of the studies. Improvements over time were seen for some items, including the description of statistics methods used, reporting of primary research outcomes, performance of power calculations, method of randomization and concealment allocation, and having performed intention-to-treat analysis.
                Despite recent improvements, reporting levels of CONSORT items in RCTs involving patients with Hodgkin lymphoma remain unsatisfactory. Further concerted action by journal editors, learned societies, and medical schools is necessary to make authors even more aware of the need to improve the reporting RCTs in medical journals to allow assessment of validity of published clinical research. Adoption of evidence-based practice (EBP) policy has implications for clinicians and researchers alike. In fields that have already adopted EBP, evidence-based practice guidelines derive from systematic reviews of research evidence. Ultimately, such guidelines serve as tools used by practitioners. Systematic reviews of treatment efficacy and effectiveness reserve their strongest endorsements for treatments that are supported by high-quality randomized clinical trials (RCTs). It is unknown how well RCTs reported in behavioral science journals fare compared to quality standards set forth in fields that pioneered the evidence-based movement. We compared analytic quality features of all behavioral health RCTs (n = 73) published in three leading behavioral journals and two leading medical journals between January 2000 and July 2003. A behavioral health trial was operationalized as one employing a behavioral treatment modality to prevent or treat an acute or chronic physical disease or condition. Findings revealed areas of weakness in analytic aspects of the behavioral health RCTs reported in both sets of journals. Weaknesses were more pronounced in behavioral journals. The authors offer recommendations for improving the analytic quality of behavioral health RCTs to ensure that evidence about behavioral treatments is highly weighted in systematic reviews.
                (c) 2006 Wiley Periodicals, Inc. The quality of randomized controlled trials (RCTs) in subfertility and their suitability for inclusion in meta-analyses have been assessed in the past and found to be insufficient. Our aim was to assess whether this quality has improved over time, particularly since the publication of the Consolidated Standards of Reporting Trials (CONSORT) statement, and to assess what proportion of trials could be included in the meta-analyses of pregnancy outcomes such as those included in Cochrane Reviews.
                A selection of subfertility trials published in 1990, 1996 and 2002 was collected from the Cochrane Menstrual Disorder and Subfertility Group (MDSG) database. Only trials published in English as full journal articles, claiming to be randomized and reporting on pregnancy outcomes, were included.
                One hundred and sixty-four trials met our inclusion criteria. Twenty-four (15%) were found not to be randomized, despite claims, and only 10 trials (6%) provided adequate details on the methods of randomization and allocation concealment. Of these, only three had sufficient details extractable to allow for an intention-to-treat analysis of the outcome 'live birth'.
                Although an improvement in some subfertility-specific issues was observed, the quality of reporting of RCTs still needs to improve to make them suitable for inclusion in meta-analyses such as those in the Cochrane Library. The pharmaceutical industry has become a major source of funding for biomedical research. Our general observation is that pharmaceutical industry employees are appearing with increasing frequency as coauthors of clinical trial publications.
                To characterize clinical trial funding, reporting, and sources; investigate author-industry affiliation; and describe clinical outcome trends over time.
                We reviewed 500 randomly selected clinical trials published in 5 influential medical journals over a 20-year period (1981-2000).
                Of the 500 clinical trials reviewed, 181 (36%) involved pharmaceutical industry as an independent (n = 104) or joint (n = 77) sponsor and 180 (36%) involved a peer-review funding source; the balance (139; 28%) lacked any declared sponsorship. The percentage of industry-sponsored clinical trials increased to 62% during 1997-2000. The percentage of nonprofit sponsored clinical trials remained constant over time, while the percentage of those without funding declaration declined. Reported author affiliation with industry increased to 66% of clinical trials sponsored only by industry. An increase in the percentage of clinical trials with reported author-industry affiliation was observed for all journals. Regardless of funding source, the majority of clinical trials reported clinical outcomes that favored the study drug.
                Pharmaceutical industry-sponsored and mixed-funding clinical trials are common, and the relative incidence of published trials with these declared funding sources in the 5 journals reviewed has increased. Industry employees are appearing as coauthors of clinical trial publications with increasing frequency. We analysed 113 reports published in 1980 in a sample of medical journals to relate features of study design to the magnitude of gains attributed to new therapies over old. Overall we rated 87 per cent of new therapies as improvements over standard therapies. The mean gain (measured by the Mann-Whitney statistic) was relatively constant across study designs, except for non-randomized controlled trials with sequential assignment to therapy, which showed a significantly higher likelihood that a patient would do better on the innovation than on standard therapy (p = 0.004). Randomized controlled trials that did not use a double-blind design had a higher likelihood of showing a gain for the innovation than did double-blind trials (p = 0.02). Any evaluation of an innovation may include both bias and the true efficacy of the new therapy, therefore we may consider making adjustments for the average bias associated with a study design. When interpreting an evaluation of a new therapy, readers should consider the impact of the following average adjustments to the Mann-Whitney statistic: for trials with non-random sequential assignment a decrease of 0.15, for non-double-blind randomized controlled trials a decrease of 0.11. The evaluation of research output, such as estimation of the proportion of treatment successes, is of ethical, scientific, and public importance but has rarely been evaluated systematically. We assessed how often experimental cancer treatments that undergo testing in randomized clinical trials (RCTs) result in discovery of successful new interventions.
                We extracted data from all completed (published and unpublished) phase 3 RCTs conducted by the National Cancer Institute cooperative groups since their inception in 1955. Therapeutic successes were determined by (1) assessing the proportion of statistically significant trials favoring new or standard treatments, (2) determining the proportion of the trials in which new treatments were considered superior to standard treatments according to the original researchers, and (3) quantitatively synthesizing data for main clinical outcomes (overall and event-free survival).
                Data from 624 trials (781 randomized comparisons) involving 216 451 patients were analyzed. In all, 30% of trials had statistically significant results, of which new interventions were superior to established treatments in 80% of trials. The original researchers judged that the risk-benefit profile favored new treatments in 41% of comparisons (316 of 766). Hazard ratios for overall and event-free survival, available for 614 comparisons, were 0.95 (99% confidence interval [CI], 0.93-0.98) and 0.90 (99% CI, 0.87- 0.93), respectively, slightly favoring new treatments. Breakthrough interventions were discovered in 15% of trials.
                Approximately 25% to 50% of new cancer treatments that reach the stage of assessment in RCTs will prove successful. The pattern of successes has become more stable over time. The results are consistent with the hypothesis that the ethical principle of equipoise defines limits of discoverability in clinical research and ultimately drives therapeutic advances in clinical medicine. Abstract Failure to identify all relevant reports of controlled trials is a potential source of bias in systematic reviews of health-care interventions. The present study aims to identify how many reports of trials -initially published as conference abstracts in the Australian and New Zealand Journal of Medicine were subsequently published in full. We identified trial reports by handsearching conference abstracts published in the Journal from 1980 to 2000. We then searched the Cochrane Controlled Trials Register and PubMed to determine how many of these had been subsequently published in full. A total of 962 reports of controlled trials was identified from the conference proceedings of 17 medical societies. Of these, 589 (61%) reports of trials were subsequently published in full, and on average within 1-2 years. Handsearching conference abstracts identified a large number of reports of controlled trials, over one-third of which were unpublished and therefore not easily accessible. This study presents a meta-analysis of the influence of several potentially biasing factors (eg industry support, extrapyramidal side effects) on efficacy of studies comparing second-generation antipsychotic (SGA) with first-generation antipsychotic (FGA) medications. We used the dataset from our previously published meta-analysis of 124 randomized controlled trials (RCTs) comparing SGAs with FGAs, to evaluate whether certain possible biases could influence the actual outcome on the total score of the Positive and Negative Syndrome Scale (PANSS), Brief Psychiatric Rating Scale (BPRS), and Clinical Global Impressions (CGI) scores. Industry sponsorship was determined by contact with authors or publication statement. We calculated whether (1) industry sponsorship, (2) study quality, (3) extrapyramidal symptoms (EPS) properties, or (4) prophylactic antiparkinsonian medications influenced SGA vs FGA efficacy for each drug and averaged overall by two Hedges and Olkin-based meta-analyses. The analysis found that none of the factors was significantly associated with a particular outcome. While industry-sponsored articles may conclude their medication to be more favorable than that of a competitor in an RCT, we found that the observed efficacy was not influenced by sponsorship. Many attribute the finding that SGAs appears to be more efficacious than FGAs to be a result of EPS-decreasing efficacy (or its measurement). We were unable to confirm that the drug's EPS properties or antiparkinsonian management altered actual efficacy. We investigated the influence of indicators of methodological quality on study outcome in a set of 89 placebo-controlled clinical trials of homoeopathy in three different ways: (1) The results of studies meeting single criteria (explicit statement of random allocation, allocation concealment, double-blinding, completeness of follow-up) of methodological quality were compared with those of studies not meeting the criteria in univariate and multivariate analyses; (2) The results of studies scoring above and below predefined scores in two quality assessment scales were compared; (3) Primary studies were consecutively entered into a cumulative meta-analysis according to the summary scores derived from the quality assessment scales. All analyses were performed using meta-regression methods. Studies that were explicitly randomized and were double-blind as well as studies scoring above the cut-points yielded significantly less positive results than studies not meeting the criteria. In the cumulative meta-analyses, there was a trend for increasing effect sizes when more studies with lower-quality scores were added. However, there was no linear relationship between quality scores and study outcome. We conclude that in the study set investigated, there was clear evidence that studies with better methodological quality tended to yield less positive results. Because summarizing disparate study features into a single score is problematic, meta-regression methods simultaneously investigating the influence of single study features seem the best method for investigating the impact of study quality on outcome. To compare the efficiency and ease of use of internet data capture compared with conventional paper based data recording in the conduct of a clinical trial.
                Multicentre, cluster randomized clinical trial.
                General practice in the UK.
                Timings for study landmarks, queries, data entry and monitoring time; Investigator Questionnaire Results.
                The internet-derived database was ready for release 33 days after the last patient visit compared with 48 days for the paper-derived database, despite much higher numbers of patients in the internet group. The mean times from visit to data entry were 10.2 (SD 18.9) days and 95.4 (SD 44.6) days respectively (P < 0.01). The mean times from a visit to a query being resolved were 121.4 (SD 58.3) days and 182.1 (SD 58.9) days respectively (P < 0.01). The post-study responses from investigators were positive. Seventy-one percent of centres said they would prefer to use the internet rather than paper CRFs for future studies.
                There were efficiency gains seen with the use of an internet-based system when compared with a paper-based system in terms data entry, query resolution and the time to the release of the database. The investigators' response to the internet system was generally favourable although on average investigators reported increased time spent on the study. Further efficiency might be gained with improved programming, increased investigator familiarity with the internet system, and with newly adapted working practices for sponsors' monitors and database personnel. To report acceptability, feasibility, and outcome data from a randomized clinical trial (RCT) of a brief intervention for caregivers of children newly diagnosed with cancer.
                Eighty-one families were randomly assigned following collection of baseline data to Intervention or Treatment as Usual (TAU). Recruitment and retention rates and progression through the protocol were tracked. Measures of state anxiety and posttraumatic stress symptoms served as outcomes.
                Difficulties enrolling participants included a high percentage of newly diagnosed families failing to meet inclusion criteria (40%) and an unexpectedly low participation rate (23%). However, movement through the protocol was generally completed in a timely manner and those completing the intervention provided positive feedback. Outcome data showed no significant differences between the arms of the RCT.
                There are many challenges inherent in conducting a RCT shortly after cancer diagnosis. Consideration of alternative research designs and optimal timing for interventions are essential next steps. Publication bias toward studies that favor new therapies has been known to occur for the past 40 years, yet its implications are not well studied in child health. The increased interest in meta-analyses has highlighted the need to identify the totality of evidence when addressing treatment questions.
                To measure the percentage of randomized controlled trials (RCTs) presented at a major pediatric scientific meeting that were subsequently published as full-length articles, to investigate factors associated with publication, and to describe the variables that change from abstract to manuscript form.
                The scientific proceedings from the Society for Pediatric Research were hand searched for RCTs (1992-1995). Subsequent publication was ascertained through a search of various electronic databases. Quality of abstracts and manuscripts was measured, and data were extracted using a structured form.
                A total of 264 (59.1%) of 447 abstracts were subsequently published. Almost 64% of RCTs that were subsequently published favored new therapy compared with 43.5% of studies that were never published (P<.001). Mean effect size for published vs unpublished RCTs was 0.74 vs 0.05 (P<.001). Median sample size was larger in published (n = 45) vs unpublished (n = 34) RCTs (P =.02). Quality was significantly lower for abstracts vs published RCTs (P<.001). For 5% of abstracts that were subsequently published, the conclusion regarding treatment efficacy changed.
                Publication bias is a serious threat to assessing the effectiveness of interventions in child health, as little more than half of RCTs presented at a major scientific meeting are subsequently published. There is a need to institute an international registry of RCTs in children so that the totality of evidence can be accessed when assessing treatment effectiveness. Randomized controlled trials (RCTs) are the best tool to evaluate the effectiveness of clinical interventions. The CONSORT (Consolidated Standards of Reporting Trials) statement is an evidence-based approach to improve the quality of RCTs. The aim of this study was to evaluate the reporting quality of published RCTs concerning myeloid hematologic malignancies according to the CONSORT statement.
                PubMed was searched for English-language RCTs involving patients with acute myeloid leukemia (AML), chronic myeloid leukemia (CML) and myelodysplastic syndromes (MDS). Trials were considered eligible when participants were randomly assigned to at least two treatment arms and included patients with AML, CML or MDS. Quality of reporting was assessed using a 24-item questionnaire based on the CONSORT checklist. Reporting was assessed in one pre-CONSORT (1988-1995) and one post-CONSORT (1996-2008) period. The effect of CONSORT statement in high- and low-ranked journals, according to their impact factor, has also been evaluated.
                The search identified 261 eligible articles for analysis. Only 13 of the 24 items of CONSORT statement were addressed in 75% or more of the studies. Most items concerning the methodological issues were reported by fewer than 50% of the studies. Significant improvements over time were seen for items that assessed the methodological quality, while RCTs published in high-ranked journals showed better quality of reporting.
                Quality of reporting in RCTs focusing on myeloid malignancies remains unsatisfactory. Further improvement of reporting is necessary to assess the validity of clinical research. When faced with a therapeutic issue, the practice of evidence-based medicine requires efficient access to information derived from controlled clinical trials. The objectives of the study were to locate, with the greatest possible exhaustivity, all controlled clinical trials published in Spanish journals of general medicine, between 1971 and 1995 (25 years), to characterize them, and to incorporate them into the worldwide database of clinical trials maintained by the Cochrane Collaboration.
                The controlled clinical trials have been identified by a systematic, manual review of all the Spanish journals of general and internal medicine. The results obtained have been compared with an exclusive electronic search in MEDLINE. A descriptive analysis of the characteristics of the localized controlled clinical trials was done.
                68 journals of general and internal medicine have been identified, only 6 being indexed in MEDLINE. A search carried out exclusively using MEDLINE would imply the loss of one third of all controlled clinical trials. About 16 controlled clinical trials per year have been published in Spain in the area of general and internal medicine, most of them with important missing information.
                The limitations of searching only in MEDLINE have been shown once again. There are few controlled clinical trials published in Spain in the area of general and internal medicine, and in order to improve their quality and their diffusion is recommended that authors and editors adhered to the international consensus initiatives that are under way. 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. Studies of drug treatments are more likely to report favourable outcomes when they are funded by the pharmaceutical industry. We compared drug trials reported in three major psychiatric journals to investigate these influences. Independent studies were more likely to report negative findings than industry-funded studies. However, the involvement of a drug company employee had a much greater effect on study outcome than financial sponsorship alone. Significant resources and time are invested in the production of research knowledge. The primary objective of this randomized controlled trial was to evaluate the effectiveness of three knowledge translation and exchange strategies in the incorporation of research evidence into public health policies and programs.
                This trial was conducted with a national sample of public health departments in Canada from 2004 to 2006. The three interventions, implemented over one year in 2005, included access to an online registry of research evidence; tailored messaging; and a knowledge broker. The primary outcome assessed the extent to which research evidence was used in a recent program decision, and the secondary outcome measured the change in the sum of evidence-informed healthy body weight promotion policies or programs being delivered at health departments. Mixed-effects models were used to test the hypotheses.
                One hundred and eight of 141 (77%) health departments participated in this study. No significant effect of the intervention was observed for primary outcome (p < 0.45). However, for public health policies and programs (HPPs), a significant effect of the intervention was observed only for tailored, targeted messages (p < 0.01). The treatment effect was moderated by organizational research culture (e.g., value placed on research evidence in decision making).
                The results of this study suggest that under certain conditions tailored, targeted messages are more effective than knowledge brokering and access to an online registry of research evidence. Greater emphasis on the identification of organizational factors is needed in order to implement strategies that best meet the needs of individual organizations.
                The trial registration number and title are as follows: ISRCTN35240937 -- Is a knowledge broker more effective than other strategies in promoting evidence-based physical activity and healthy body weight programming?
Most trials have been designed and reported poorly, resulting in a lack of evidence for potentially beneficial treatments. There is a desperate need for large well conducted studies that evaluate long-term effects of current therapies. We suggest the creation of an international platform to improve quality and standardization of future trials in order to inform clinical practice.