Dataset Information

Assessing imprecision in Cochrane systematic reviews: a comparison of GRADE and Trial Sequential Analysis.

ABSTRACT:

Background

The evaluation of imprecision is a key dimension of the grading of the confidence in the estimate. Grading of Recommendations Assessment, Development and Evaluation (GRADE) gives recommendations on how to downgrade evidence for imprecision, but authors vary in their use. Trial Sequential Analysis (TSA) has been advocated for a more reliable assessment of imprecision. We aimed to evaluate reporting of and adherence to GRADE and to compare the assessment of imprecision of intervention effects assessed by GRADE and TSA in Cochrane systematic reviews.

Methods

In this cross-sectional study, we included 100 Cochrane reviews irrespective of type of intervention with a key dichotomous outcome meta-analyzed and assessed by GRADE. The methods and results sections of each review were assessed for adequacy of imprecision evaluation. We re-analyzed imprecision following the GRADE Handbook and the TSA Manual.

Results

Overall, only 13.0% of reviews stated the criteria they applied to assess imprecision. The most common dimensions were the 95% width of the confidence intervals and the optimal information size. Review authors downgraded 48.0% of key outcomes due to imprecision. When imprecision was re-analyzed following the GRADE Handbook, 64% of outcomes were downgraded. Agreement between review authors' assessment and assessment by the authors of this study was moderate (kappa 0.43, 95% confidence interval [CI] 0.23 to 0.58). TSA downgraded 69.0% outcomes due to imprecision. Agreement between review authors' GRADE assessment and TSA, irrespective of downgrading levels, was moderate (kappa 0.43, 95% CI 0.21 to 0.57). Agreement between our GRADE assessment following the Handbook and TSA was substantial (kappa 0.66, 95% CI 0.49 to 0.79).

Conclusions

In a sample of Cochrane reviews, methods for assessing imprecision were rarely reported. GRADE according to Handbook guidelines and TSA led to more severe judgment of imprecision rather than GRADE adopted by reviews' authors. Cochrane initiatives to improve adherence to GRADE Handbook are warranted. TSA may transparently assist in such development.

SUBMITTER: Castellini G

PROVIDER: S-EPMC6064621 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Assessing imprecision in Cochrane systematic reviews: a comparison of GRADE and Trial Sequential Analysis.

Castellini Greta G Castellini Greta G Bruschettini Matteo M Gianola Silvia S Gluud Christian C Moja Lorenzo L

Systematic reviews 20180728 1

<h4>Background</h4>The evaluation of imprecision is a key dimension of the grading of the confidence in the estimate. Grading of Recommendations Assessment, Development and Evaluation (GRADE) gives recommendations on how to downgrade evidence for imprecision, but authors vary in their use. Trial Sequential Analysis (TSA) has been advocated for a more reliable assessment of imprecision. We aimed to evaluate reporting of and adherence to GRADE and to compare the assessment of imprecision of interv ...[more]

PMID: 30055658

Similar Datasets

Project description:BackgroundSystematic reviews support health systems and clinical decision-making by identifying and summarizing all existing studies on a particular topic. In 2009, a comprehensive description of child-relevant systematic reviews published in the Cochrane Database of Systematic Reviews was compiled. This study aims to provide an update, and to describe these systematic reviews according to their content and methodological approaches.MethodsAll child-relevant systematic reviews published by the Cochrane Collaboration in the Cochrane Database of Systematic Reviews (CDSR) as of March, 2013 were identified and described in relation to their content and methodological approaches. This step equated to an update of the Child Health Field Review Register (CHFRR). The content of the updated CHFRR was compared to the published 2009 CHFRR description regarding clinical and methodological characteristics, using bivariate analyses. As the Cochrane Collaboration has recognized that disease burden should guide research prioritization, we extracted data from the Global and National Burden of Diseases and Injuries Among Children and Adolescents Between 1990 and 2013 study in order to map the distribution of the burden of disease in child health to the distribution of evidence across Review Groups in the CHFRR.ResultsOf the 5,520 potential Cochrane systematic reviews identified, 1,293 (23.4%) were child-relevant (an increase of 24% since 2009). Overall, these reviews included 16,738 primary studies. The most commonly represented Review Groups were Airways (11.5%), Cystic Fibrosis and Genetic Diseases (7.9%), Acute Respiratory Infections (7.8%), Developmental, Psychological and Learning Problems (6.7%), and Infectious Diseases (6.2%). Corresponding authors were most often from Europe (51%), North America (15%), and Australia (15%). The majority of systematic reviews examined pharmacological interventions alone (52% compared to 59% in 2009). Out of 611 reviews that were assessed as up-to-date, GRADE was used in 204 (35%) reviews to assess the overall quality of the evidence, which was often moderate (35.6%) or low (37.8%) for primary outcomes. Ninety percent of reviews that were assessed as up to date used the Cochrane Risk of Bias tool, or a modified version, to assess methodological quality. Most reviews conducted one or more meta-analyses (73%). Among the 25 leading causes of death globally, the Review Groups associated with the largest number of causes were: 1) Infectious Diseases, 2) Anaesthesia, Critical, and Emergency Care, 3) Injuries, 4) Pregnancy and Childbirth (PC), and 5) Neonatal. There were large discrepancies between the number of causes of mortality that each Review Group was associated with and the total amount of evidence each Review Group contributed to the CHFRR. Ninety-eight percent of the causes of mortality in 2013 were from developing nations, but only 224 (17.3%) reviews had corresponding authors from developing countries.ConclusionThe content and methodological characteristics of child-relevant systematic reviews in the Cochrane CHFRR have been described in detail. There were modest advances in methods between 2009 and 2013. Systematic reviews contained in the CDSR offer an important resource for researcher's, clinicians and policy makers by synthesizing an extensive body of primary research. Further content analysis will allow the identification of clinical topics of greatest priority for future systematic reviews in child health.

Project description:BACKGROUND:Consumers, clinicians, policymakers and researchers require high quality evidence to guide decision-making in child health. Though Cochrane systematic reviews (SRs) are a well-established source of evidence, little is known about the characteristics of non-Cochrane child-relevant SRs. To complement published descriptions of Cochrane SRs, we aimed to characterize the epidemiologic, methodological, and reporting qualities of non-Cochrane child-relevant SRs published in 2014. METHODS:English-language child-relevant SRs of quantitative primary research published outside the Cochrane Library in 2014 were eligible for this descriptive analysis. A research librarian searched MEDLINE, CINAHL, Web of Science, and PubMed in August 2015. A single reviewer screened articles for inclusion; a second verified the excluded studies. Reviewers extracted: general characteristics of the review; included study characteristics; methodological approaches. We performed univariate analyses and presented the findings narratively. RESULTS:We identified 1598 child-relevant SRs containing a median (IQR) 19 (11, 33) studies. These originated primarily from high-income countries (n?=?1247, 78.0%) and spanned 47 of the 53 Cochrane Review Groups. Most synthesized therapeutic (n?=?753, 47.1%) or epidemiologic (n?=?701, 43.8%) evidence. Though 39.3% (n?=?628) of SRs included evidence related to children only, few were published in pediatric-specific journals (n?=?283, 17.7%). Reporting quality seemed poor based on the items we assessed; few reviews mentioned an a-priori protocol (n?=?246, 15.4%) or registration (n?=?111, 6.9%), and only 23.4% (n?=?374) specified a primary outcome. Many SRs relied solely on evidence from non-RCTs (n?=?796, 49.8%). Less than two-thirds (n?=?953, 59.6%) appraised the quality of included studies and assessments of the certainty of the body of evidence were rare (n?=?102, 6.4%). CONCLUSIONS:Child-relevant Cochrane SRs are a known source of high quality evidence in pediatrics. There exists, however, an abundance of evidence from non-Cochrane SRs that may be complementary. Our findings show that high-quality non-Cochrane SRs may not be practical nor easy for knowledge users to find. Improvements are needed to ensure that evidence syntheses published outside of the Cochrane Library adhere to the high standard of conduct and reporting characteristic of Cochrane SRs.

Project description:BackgroundPrevious research on data extraction methods in systematic reviews has focused on single aspects of the process. We aimed to provide a deeper insight into these methods by analysing a current sample of reviews.MethodsWe included systematic reviews of health interventions in humans published in English. We analysed 75 Cochrane reviews from May and June 2020 and a random sample of non-Cochrane reviews published in the same period and retrieved from Medline. We linked reviews with protocols and study registrations. We collected information on preparing, piloting, and performing data extraction and on use of software to assist review conduct (automation tools). Data were extracted by one author, with 20% extracted in duplicate. Data were analysed descriptively.ResultsOf the 152 included reviews, 77 reported use of a standardized extraction form (51%); 42 provided information on the type of form used (28%); 24 on piloting (16%); 58 on what data was collected (38%); 133 on the extraction method (88%); 107 on resolving disagreements (70%); 103 on methods to obtain additional data or information (68%); 52 on procedures to avoid data errors (34%); and 47 on methods to deal with multiple study reports (31%). Items were more frequently reported in Cochrane than non-Cochrane reviews. The data extraction form used was published in 10 reviews (7%). Use of software was rarely reported except for statistical analysis software and use of RevMan and GRADEpro GDT in Cochrane reviews. Covidence was the most frequent automation tool used: 18 reviews used it for study selection (12%) and 9 for data extraction (6%).ConclusionsReporting of data extraction methods in systematic reviews is limited, especially in non-Cochrane reviews. This includes core items of data extraction such as methods used to manage disagreements. Few reviews currently use software to assist data extraction and review conduct. Our results can serve as a baseline to assess the uptake of such tools in future analyses.

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.

Dataset Information

Assessing imprecision in Cochrane systematic reviews: a comparison of GRADE and Trial Sequential Analysis.

Background

Methods

Results

Conclusions

Publications

Assessing imprecision in Cochrane systematic reviews: a comparison of GRADE and Trial Sequential Analysis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets