Trial registration in Latin America and the Caribbean’s: study of randomized trials published in 2010

Revéiz, Ludovic; Bonfill, Xavier; Glujovsky, Demián; Pinzón, Carlos E; Asenjo‐Lobos, Claudia; Cortes, Marcela; Cañón, Martín; Bardach, Ariel; Comandé, Daniel; Zorrilla, Andrés Felipe Cardona

doi:10.1016/j.jclinepi.2011.09.003

Cited by 25 publications

(36 citation statements)

References 6 publications

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“…Twenty five studies were excluded; eight were not inception cohorts [35]–[42]; in two studies, the authors of included RCTs were not contacted for information on publication [43], [44]; in six, only published studies were included in the cohort [45]–[50]; in six studies, trial registries were investigated and were not considered as inception cohorts [51]–[56]; in one we could not confirm if any of the included studies were RCTs [57]; the author of a letter confirmed the study mentioned never began [58] and in a further study [59] was an analysis on oral presentations from one of the included studies [7].…”

Section: Resultsmentioning

confidence: 99%

Systematic Review of the Empirical Evidence of Study Publication Bias and Outcome Reporting Bias — An Updated Review

et al. 2013

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BackgroundThe increased use of meta-analysis in systematic reviews of healthcare interventions has highlighted several types of bias that can arise during the completion of a randomised controlled trial. Study publication bias and outcome reporting bias have been recognised as a potential threat to the validity of meta-analysis and can make the readily available evidence unreliable for decision making.Methodology/Principal FindingsIn this update, we review and summarise the evidence from cohort studies that have assessed study publication bias or outcome reporting bias in randomised controlled trials. Twenty studies were eligible of which four were newly identified in this update. Only two followed the cohort all the way through from protocol approval to information regarding publication of outcomes. Fifteen of the studies investigated study publication bias and five investigated outcome reporting bias. Three studies have found that statistically significant outcomes had a higher odds of being fully reported compared to non-significant outcomes (range of odds ratios: 2.2 to 4.7). In comparing trial publications to protocols, we found that 40–62% of studies had at least one primary outcome that was changed, introduced, or omitted. We decided not to undertake meta-analysis due to the differences between studies.ConclusionsThis update does not change the conclusions of the review in which 16 studies were included. Direct empirical evidence for the existence of study publication bias and outcome reporting bias is shown. There is strong evidence of an association between significant results and publication; studies that report positive or significant results are more likely to be published and outcomes that are statistically significant have higher odds of being fully reported. Publications have been found to be inconsistent with their protocols. Researchers need to be aware of the problems of both types of bias and efforts should be concentrated on improving the reporting of trials.

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Section: Resultsmentioning

confidence: 99%

Systematic Review of the Empirical Evidence of Study Publication Bias and Outcome Reporting Bias — An Updated Review

et al. 2013

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“…Databases were searched for articles that listed a first author or contact author whose affiliate institution was in LAC (see supporting information: Appendix S1: search strategy). A previous publication evaluating the prevalence of trial registration and comparing methodological characteristics between registered and non-registered RCT used the same set of trials [19].…”

Section: Methodsmentioning

confidence: 99%

Characteristics of Randomized Trials Published in Latin America and the Caribbean According to Funding Source

et al. 2013

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IntroductionFew studies have assessed the nature and quality of randomized controlled trials (RCTs) in Latin America and the Caribbean (LAC).Methods and FindingsThe aims of this systematic review are to evaluate the characteristics (including the risk of bias assessment) of RCT conducted in LAC according to funding source. A review of RCTs published in 2010 in which the author's affiliation was from LAC was performed in PubMed and LILACS. Two reviewers independently extracted data and assessed the risk of bias. The primary outcomes were risk of bias assessment and funding source. A total of 1,695 references were found in PubMed and LILACS databases, of which 526 were RCTs (N = 73.513 participants). English was the dominant publication language (93%) and most of the RCTs were published in non-LAC journals (84.2%). Only five of the 19 identified countries accounted for nearly 95% of all RCTs conducted in the region (Brazil 70.9%, Mexico 10.1%, Argentina 5.9%, Colombia 3.8%, and Chile 3.4%). Few RCTs covered priority areas related with Millennium Development Goals like maternal health (6.7%) or high priority infectious diseases (3.8%). Regarding children, 3.6% and 0.4% RCT evaluated nutrition and diarrhea interventions respectively but none pneumonia. As a comparison, aesthetic and sport related interventions account for 4.6% of all trials. A random sample of RCTs (n = 358) was assessed for funding source: exclusively public (33.8%); private (e.g. pharmaceutical company) (15.3%); other (e.g. mixed, NGO) (15.1%); no funding (35.8%). Overall assessments for risk of bias showed no statistically significant differences between RCTs and type of funding source. Statistically significant differences favoring private and others type of funding was found when assessing trial registration and conflict of interest reporting.ConclusionFindings of this study could be used to provide more direction for future research to facilitate innovation, improve health outcomes or address priority health problems.

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“…In the UK, the bulk of disease management is already delivered through primary care. Primary care is generally defined in terms of attributes such as a gatekeeping function and first contact care [17], but other attributes also make it an excellent platform for self-management support. Primary care offers open access between the health service and the population, can deliver continuity of care through an extended personal relationship or through informational continuity, and has a role in helping patients achieve care that balances compliance with clinical guidelines and consistency with patient needs and preferences.…”

Section: Introductionmentioning

confidence: 99%

A cluster randomised controlled trial of the clinical and cost-effectiveness of a 'whole systems' model of self-management support for the management of long- term conditions in primary care: trial protocol

et al. 2012

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BackgroundPatients with long-term conditions are increasingly the focus of quality improvement activities in health services to reduce the impact of these conditions on quality of life and to reduce the burden on care utilisation. There is significant interest in the potential for self-management support to improve health and reduce utilisation in these patient populations, but little consensus concerning the optimal model that would best provide such support. We describe the implementation and evaluation of self-management support through an evidence-based 'whole systems' model involving patient support, training for primary care teams, and service re-organisation, all integrated into routine delivery within primary care.MethodsThe evaluation involves a large-scale, multi-site study of the implementation, effectiveness, and cost-effectiveness of this model of self-management support using a cluster randomised controlled trial in patients with three long-term conditions of diabetes, chronic obstructive pulmonary disease (COPD), and irritable bowel syndrome (IBS). The outcome measures include healthcare utilisation and quality of life. We describe the methods of the cluster randomised trial.DiscussionIf the 'whole systems' model proves effective and cost-effective, it will provide decision-makers with a model for the delivery of self-management support for populations with long-term conditions that can be implemented widely to maximise 'reach' across the wider patient population.Trial registration numberISRCTN: ISRCTN90940049

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Trial registration in Latin America and the Caribbean’s: study of randomized trials published in 2010

Cited by 25 publications

References 6 publications

Systematic Review of the Empirical Evidence of Study Publication Bias and Outcome Reporting Bias — An Updated Review

Systematic Review of the Empirical Evidence of Study Publication Bias and Outcome Reporting Bias — An Updated Review

Characteristics of Randomized Trials Published in Latin America and the Caribbean According to Funding Source

A cluster randomised controlled trial of the clinical and cost-effectiveness of a 'whole systems' model of self-management support for the management of long- term conditions in primary care: trial protocol

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