Dataset Information

The judgement of biases included in the category "other bias" in Cochrane systematic reviews of interventions: a systematic survey.

ABSTRACT:

Background

Clinical decisions are made based on Cochrane reviews, but the implementation of results of evidence syntheses such as Cochrane reviews is problematic if the evidence is not prepared consistently. All systematic reviews should assess the risk of bias (RoB) in included studies, and in Cochrane reviews, this is done by using Cochrane RoB tool. However, the tool is not necessarily applied according to the instructions. In this study, we aimed to determine the types of bias and their corresponding judgements noted in the 'other bias' domain of Cochrane RoB tool.

Methods

We analyzed Cochrane reviews that included randomized controlled trials (RCTs) and extracted data regarding 'other bias' from the RoB table and accompanying support for the judgment. We categorized different types of other bias.

Results

We analyzed 768 Cochrane reviews that included 11,369 RCTs. There were 602 (78%) Cochrane reviews that had 'other bias' domain in the RoB tool, and they included a total of 7811 RCTs. In the RoB table of 337 Cochrane reviews for at least one of the included trials it was indicated that no other bias was found and supporting explanations were inconsistently judged as low, unclear or high RoB. In the 524 Cochrane reviews that described various sources of other bias, there were 5762 individual types of explanations which we categorized into 31 groups. The judgments of the same supporting explanations were highly inconsistent. We found numerous other inconsistencies in reporting of sources of other bias in Cochrane reviews.

Conclusion

Cochrane authors mention a wide range of sources of other bias in the RoB tool and they inconsistently judge the same supporting explanations. Inconsistency in appraising risk of other bias hinders reliability and comparability of Cochrane systematic reviews. Discrepant and erroneous judgments of bias in evidence synthesis may hinder implementation of evidence in routine clinical practice and reduce confidence in otherwise trustworthy sources of information. These results can help authors of Cochrane and non-Cochrane reviews to gain insight into various sources of other bias that can be found in trials, and also to help them avoid mistakes that were recognized in published Cochrane reviews.

SUBMITTER: Babic A

PROVIDER: S-EPMC6458756 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature

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The judgement of biases included in the category "other bias" in Cochrane systematic reviews of interventions: a systematic survey.

Babic Andrija A Pijuk Andela A Brázdilová Lucie L Georgieva Yuliyana Y Raposo Pereira Marco António MA Poklepovic Pericic Tina T Puljak Livia L

BMC medical research methodology 20190411 1

<h4>Background</h4>Clinical decisions are made based on Cochrane reviews, but the implementation of results of evidence syntheses such as Cochrane reviews is problematic if the evidence is not prepared consistently. All systematic reviews should assess the risk of bias (RoB) in included studies, and in Cochrane reviews, this is done by using Cochrane RoB tool. However, the tool is not necessarily applied according to the instructions. In this study, we aimed to determine the types of bias and th ...[more]

PMID: 30971219

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Project description:BackgroundIn contemporary medical research, randomised controlled trials are seen as the gold standard for establishing treatment effects where it is ethical and practical to conduct them. In palliative care such trials are often impractical, unethical, or extremely difficult, with multiple methodological problems. We review the utility of Cochrane reviews in informing palliative care practice.MethodsPublished reviews in palliative care registered with the Cochrane Pain, Palliative and Supportive Care Group as of December 2007 were obtained from the Cochrane Database of Systematic Reviews, issue 1, 2008. We reviewed the quality and quantity of primary studies available for each review, assessed the quality of the review process, and judged the strength of the evidence presented. There was no prior intention to perform any statistical analyses.Results25 published systematic reviews were identified. Numbers of included trials ranged from none to 54. Within each review, included trials were heterogeneous with respect to patients, interventions, and outcomes, and the number of patients contributing to any single analysis was generally much lower than the total included in the review. A variety of tools were used to assess trial quality; seven reviews did not use this information to exclude low quality studies, weight analyses, or perform sensitivity analysis for effect of low quality. Authors indicated that there were frequently major problems with the primary studies, individually or in aggregate. Our judgment was that the reviewing process was generally good in these reviews, and that conclusions were limited by the number, size, quality and validity of the primary studies.We judged the evidence about 23 of the 25 interventions to be weak. Two reviews had stronger evidence, but with limitations due to methodological heterogeneity or definition of outcomes. No review provided strong evidence of no effect.ConclusionCochrane reviews in palliative care are well performed, but fail to provide good evidence for clinical practice because the primary studies are few in number, small, clinically heterogeneous, and of poor quality and external validity. They are useful in highlighting the weakness of the evidence base and problems in performing trials in palliative care.

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Project description:BackgroundSeveral factors are associated with an increased risk of preterm birth (PTB); therefore, various interventions might have the potential to influence it. Due to the large number of interventions that address PTB, the objective of this overview is to summarise evidence from Cochrane reviews regarding the effects and safety of these different interventions.MethodsWe conducted a systematic literature search in the Cochrane Database of Systematic Reviews. Included reviews should be based on randomised controlled trials comparing antenatal non-pharmacological and pharmacological interventions that directly or indirectly address PTB with placebo/no treatment or routine care in pregnant women at less than 37 completed weeks of gestation without signs of threatened preterm labour. We considered PTB at less than 37 completed weeks of gestation as the primary outcome.ResultsWe included 56 Cochrane systematic reviews. Three interventions increased PTB risk significantly. Twelve interventions led to a statistically significant lower incidence of PTBs. However, this reduction was mostly observed in defined at-risk subgroups of pregnant women. The remaining antenatal interventions failed to prove a significant effect on PTB?<?37 weeks, but some of them at least showed a positive effect in secondary outcomes (e.g., reduction in early PTBs). As an unintended result of this review, we identified 28 additional Cochrane reviews which intended to report on PTB?<?37 weeks, but were not able to find any RCTs reporting appropriate data.ConclusionsThe possible effects of a diverse range of interventions on PTB have been evaluated in Cochrane systematic reviews. Few interventions have been demonstrated to be effective and a small number have been found to be harmful. For around half of the interventions evaluated, the Cochrane review concluded that there was insufficient evidence to provide sound recommendations for clinical practice. No RCT evidence is available for a number of potentially relevant interventions.

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Project description:Eating disorders are psychiatric conditions originated from and perpetuated by individual, family and sociocultural factors. The psychosocial approach to treatment and prevention of relapse is crucial. To present an overview of the scientific evidence on effectiveness of psychosocial interventions in treatment of eating disorders. All systematic reviews published by the Cochrane Database of Systematic Reviews - Cochrane Library on the topic were included. Afterwards, as from the least recent date of these reviews (2001), an additional search was conducted at PubMed with sensitive search strategy and with the same keywords used. A total of 101 primary studies and 30 systematic reviews (5 Cochrane systematic reviews), meta-analysis, guidelines or narrative reviews of literature were included. The main outcomes were: symptomatic remission, body image, cognitive distortion, psychiatric comorbidity, psychosocial functioning and patient satisfaction. The cognitive behavioral approach was the most effective treatment, especially for bulimia nervosa, binge eating disorder and the night eating syndrome. For anorexia nervosa, the family approach showed greater effectiveness. Other effective approaches were interpersonal psychotherapy, dialectic behavioral therapy, support therapy and self-help manuals. Moreover, there was an increasing number of preventive and promotional approaches that addressed individual, family and social risk factors, being promising for the development of positive self-image and self-efficacy. Further studies are required to evaluate the impact of multidisciplinary approaches on all eating disorders, as well as the cost-effectiveness of some effective modalities, such as the cognitive behavioral therapy. RESUMO Transtornos alimentares são doenças psiquiátricas originadas de e perpetuadas por fatores individuais, familiares e socioculturais. A abordagem psicossocial é essencial para o tratamento e a prevenção de recaídas. Apresentar uma visão geral das evidências científicas sobre a efetividade das intervenções psicossociais no tratamento de transtornos alimentares. Foram incluídas todas as revisões sistemáticas publicadas no Banco de Dados de Revisões Sistemáticas da Cochrane Library. Posteriormente, a partir da data menos recente destas revisões (2001), realizou-se uma busca adicional no PubMed, com estratégia de busca sensibilizada e com os mesmos descritores utilizados antes. No total, foram incluídos 101 estudos primários e 30 revisões sistemáticas (5 revisões sistemáticas da Cochrane), metanálises, diretrizes ou revisões narrativas da literatura. Os principais desfechos foram remissão de sintomas, imagem corporal, distorção cognitiva, comorbidade psiquiátrica, funcionamento psicossocial e satisfação do paciente. A abordagem cognitivo-comportamental foi o tratamento mais efetivo, principalmente para bulimia nervosa, transtorno da compulsão alimentar periódica e síndrome do comer noturno. Para anorexia nervosa, a abordagem familiar demonstrou maior efetividade. Outras abordagens efetivas foram psicoterapia interpessoal, terapia comportamental dialética, terapia de apoio e manuais de autoajuda. Além disso, houve um número crescente de abordagens preventivas e promocionais que contemplaram fatores de risco individuais, familiares e sociais, sendo promissoras para o desenvolvimento da autoimagem positiva e autoeficácia. São necessários mais estudos que avaliem o impacto de abordagens multidisciplinares em todos transtornos alimentares, além da relação custo-efetividade de algumas modalidades efetivas, como a terapia cognitivo-comportamental.

Dataset Information

The judgement of biases included in the category "other bias" in Cochrane systematic reviews of interventions: a systematic survey.

Background

Methods

Results

Conclusion

Publications

The judgement of biases included in the category "other bias" in Cochrane systematic reviews of interventions: a systematic survey.

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