1,391 research outputs found

    A methodological approach for assessing the uptake of core outcome sets using ClinicalTrials.gov: findings from a review of randomised controlled trials of rheumatoid arthritis

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    Objective To assess the uptake of the rheumatoid arthritis core outcome set using a new assessment method of calculating uptake from data in clinical trial registry entries. Design Review of randomised trials. Setting ClinicalTrials.gov. Subjects 273 randomised trials of drug interventions for the treatment of rheumatoid arthritis and registered in ClinicalTrials.gov between 2002 and 2016. Full publications were identified for completed studies from information in the trial registry or from an internet search using Google and the citation database Web of Science. Main outcome measure The percentage of trials reporting or planning to measure the rheumatoid arthritis core outcome set calculated from the information presented in the trial registry and compared with the percentage reporting the rheumatoid arthritis core outcome set in the resulting trial publications. Results The full rheumatoid arthritis core outcome set was reported in 81% (116/143) of trials identified on the registry as completed (or terminated) for which results were found in either the published literature or the registry. For trials identified on the registry as completed (or terminated), using information only available in the registry gives an estimate for uptake of 77% (145/189). Conclusions The uptake of the rheumatoid arthritis core outcome set in clinical trials has continued to increase over time. Using the information on outcomes listed for completed or terminated studies in a trial registry provides a reasonable estimate of the uptake of a core outcome set and is a more efficient and up-to-date approach than examining the outcomes in published trial reports. The method proposed may provide an efficient approach for an up-to-date assessment of the uptake of the 300 core outcome sets already published

    Application and investigation of a bound for outcome reporting bias

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    BACKGROUND: Direct empirical evidence for the existence of outcome reporting bias is accumulating and this source of bias is recognised as a potential threat to the validity of meta-analysis of randomised clinical trials. METHODS: A method for calculating the maximum bias in a meta-analysis due to publication bias is adapted for the setting where within-study selective non-reporting of outcomes is suspected, and compared to the alternative approach of missing data imputation. The properties of both methods are investigated in realistic small sample situations. RESULTS: The results suggest that the adapted Copas and Jackson approach is the preferred method for reviewers to apply as an initial assessment of robustness to within-study selective non-reporting. CONCLUSION: The Copas and Jackson approach is a useful method for systematic reviewers to apply to assess robustness to outcome reporting bias

    Circulating 25-hydroxyvitamin D concentration and cause-specific mortality in the Melbourne Collaborative Cohort Study.

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    Vitamin D deficiency is associated with higher all-cause mortality, but associations with specific causes of death are unclear. We investigated the association between circulating 25-hydroxyvitamin D (25(OH)D) concentration and cause-specific mortality using a case-cohort study within the Melbourne Collaborative Cohort Study (MCCS). Eligibility for the case-cohort study was restricted to participants with baseline dried blood spot samples and no pre-baseline diagnosis of cancer. These analyses included participants who died (n = 2307) during a mean follow-up of 14 years and a sex-stratified random sample of eligible cohort participants ('subcohort', n = 2923). Concentration of 25(OH)D was measured using liquid chromatography-tandem mass spectrometry. Cox regression, with Barlow weights and robust standard errors to account for the case-cohort design, was used to estimate hazard ratios (HRs) and 95 % confidence intervals (CIs) for cause-specific mortality in relation to 25(OH)D concentration with adjustment for confounders. Circulating 25(OH)D concentration was inversely associated with risk of death due to cancer (HR per 25 nmol/L increment = 0.88, 95 % CI 0.78-0.99), particularly colorectal cancer (HR = 0.75, 95 % CI 0.57-0.99). Higher 25(OH)D concentrations were also associated with a lower risk of death due to diseases of the respiratory system (HR = 0.62, 95 % CI 0.43-0.88), particularly chronic obstructive pulmonary disease (HR = 0.53, 95 % CI 0.30-0.94), and diseases of the digestive system (HR = 0.44, 95 % CI 0.26-0.76). Estimates for diabetes mortality (HR = 0.64, 95 % CI 0.33-1.26) and cardiovascular disease mortality (HR = 0.90, 95 % CI 0.76-1.07) lacked precision. The findings suggest that vitamin D might be important for preventing death due to some cancers, respiratory diseases, and digestive diseases

    Individual patient data meta-analysis : Cervical stitch (cerclage) for preventing pregnancy loss in women

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    BACKGROUND: Cervical cerclage is a surgical procedure involving suturing the cervix with a purse type stitch to keep it closed during pregnancy. This procedure has been used widely in the management of pregnancies considered at high risk of preterm delivery. Several observational studies into the efficacy of cervical cerclage have claimed high rates of successful pregnancy outcome in women with a poor obstetric history attributed to cervical incompetence. However, a recent aggregate data Cochrane review found no such conclusive evidence from seven included randomised studies. Current data suggests that cervical cerclage is likely to benefit women considered to be 'at very high risk' of a second trimester miscarriage due to a cervical factor, however identifying such women remains elusive and many women may be treated unnecessarily. Undertaking an individual patient data (IPD) meta-analysis of the studies will allow us to investigate whether treatment is more effective in particular subgroups. Such an analysis will also provide a more powerful analysis of the predictors of preterm delivery and pregnancy loss, including ultrasound measurement of cervical length, and will allow a more complete analysis of 'time to event' outcomes. METHODS/DESIGN: The analysis will include data from randomised trials comparing the intervention of elective cerclage versus no cerclage or bedrest to prevent miscarriage or pre-term labour. A specific list of data will be requested for each trial, including demographic and obstetric history data. The primary outcomes of interest will be neonatal mortality/morbidity. Attention will also be given to secondary outcomes such as time from randomisation to delivery, preterm delivery before 32 weeks and maternal morbidity. An intention to treat analysis will be performed, with attention paid to assessing clinical and statistical heterogeneity. Multilevel models with patients and trials as the two levels will be explored to investigate treatment effect on various outcomes. Patient-level covariates will be incorporated into the models in an attempt to account for statistical heterogeneity as well as to investigate interactions with treatment effect. DISCUSSION: Predictive models generated from our analysis should lead to more effective counselling of women at risk and a more cost effective use of cerclage

    Assessing the impact of a research funder’s recommendation to consider core outcome sets

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    Background Core outcome sets (COS) have the potential to reduce waste in research by improving the consistency of outcomes measured in trials of the same health condition. However, this reduction in waste will only be realised through the uptake of COS by clinical trialists. Without uptake, the continued development of COS that are not implemented may add to waste in research. Funders of clinical trials have the potential to have an impact on COS uptake by recommending their use to those applying for funding. The aim of our study was to assess the extent to which applicants followed the National Institute for Health Research Health Technology Assessment (NIHR HTA) programme’s recommendation to search for a COS to include in their clinical trial. Methods and findings We examined the outcomes section and detailed project descriptions of all 95 researcher-led primary research applications submitted to the NIHR HTA between January 2012, when the recommendation to search for a COS was included in the guidance for applicants, and December 2015 for evidence that a search for a COS had taken place and rationale for outcome choice in the absence of COS. A survey of applicants was conducted to further explore their use of COS and choice of outcomes with a response rate of 49%. Nine out of 95 applicants (10%) stated in their application that they had searched the COMET (Core Outcome Measures for Effectiveness Trials) Initiative database for a COS and another nine referred to searching for a COS using another method, e.g. a review of the literature. Of the 77 (81%) applicants that did not mention COMET or COS in their application, eight stated in the survey that they had searched the COMET database and ten carried out a search using another method. Some applicants who did not search for a COS gave reasons for their choice of outcomes including taking advice from patients and the public and choosing outcomes used in previous trials. Conclusion A funding body can have an impact on COS uptake by encouraging trialists to search for a COS. Funders could take further steps by putting processes in place to prompt applicants to be explicit about searching for COS in their application and notifying the funding board if a search has not taken place. The sources of information used by trialists to make decisions about outcomes in the absence of COS may suggest methods of dissemination for COS

    Development of a core outcome set for clinical trials in childhood asthma: a survey of clinicians, parents, and young people

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    In clinical trials in childhood asthma, outcomes reflecting short-term disease activity are frequently measured, whilst functional status, quality of life (QoL), and long-term treatment effects are rarely assessed. There is also non-uniformity across studies in the selection and measurement of outcomes within these domains. The development of a core outcome set has the potential to reduce heterogeneity between trials, lead to research that is more likely to have measured relevant outcomes, and enhance the value of evidence synthesis by reducing the risk of outcome reporting bias and ensuring that all trials contribute usable information

    The iBRA (implant breast reconstruction evaluation) study: protocol for a prospective multi-centre cohort study to inform the feasibility, design and conduct of a pragmatic randomised clinical trial comparing new techniques of implant-based breast reconstruction.

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    BACKGROUND: Implant-based breast reconstruction (IBBR) is the most commonly performed reconstructive procedure in the UK. The introduction of techniques to augment the subpectoral pocket has revolutionised the procedure, but there is a lack of high-quality outcome data to describe the safety or effectiveness of these techniques. Randomised controlled trials (RCTs) are the best way of comparing treatments, but surgical RCTs are challenging. The iBRA (implant breast reconstruction evaluation) study aims to determine the feasibility, design and conduct of a pragmatic RCT to examine the effectiveness of approaches to IBBR. METHODS/DESIGN: The iBRA study is a trainee-led research collaborative project with four phases:Phase 1 - a national practice questionnaire (NPQ) to survey current practicePhase 2 - a multi-centre prospective cohort study of patients undergoing IBBR to evaluate the clinical and patient-reported outcomesPhase 3- an IBBR-RCT acceptability survey and qualitative work to explore patients' and surgeons' views of proposed trial designs and candidate outcomes.Phase 4 - phases 1 to 3 will inform the design and conduct of the future RCT All centres offering IBBR will be encouraged to participate by the breast and plastic surgical professional associations (Association of Breast Surgery and British Association of Plastic Reconstructive and Aesthetic Surgeons). Data collected will inform the feasibility of undertaking an RCT by defining current practice and exploring issues surrounding recruitment, selection of comparator arms, choice of primary outcome, sample size, selection criteria, trial conduct, methods of data collection and feasibility of using the trainee collaborative model to recruit patients and collect data. DISCUSSION: The preliminary work undertaken within the iBRA study will determine the feasibility, design and conduct of a definitive RCT in IBBR. It will work with the trainee collaborative to build capacity by creating an infrastructure of research-active breast and plastic surgeons which will facilitate future high-quality research that will ultimately improve outcomes for all women seeking reconstructive surgery. TRIAL REGISTRATION: ISRCTN37664281
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