Statistical heterogeneity in systematic reviews of clinical trials: a critical appraisal of guidelines and practice

2002 ◽  
Vol 7 (1) ◽  
pp. 51-61 ◽  
Author(s):  
Julian Higgins ◽  
Simon Thompson ◽  
Jonathan Deeks ◽  
Douglas Altman
Keyword(s):  
Clinical Trials ◽  
Systematic Reviews ◽  
Current Practice ◽  
Meta Analysis ◽  
A Priori ◽  
Potential Effect ◽  
Cochrane Reviews ◽  
Study Results ◽  
Statistical Heterogeneity ◽  
Meta Regression

Objective: Heterogeneity between study results can be a problem in any systematic review or meta-analysis of clinical trials. Identifying its presence, investigating its cause and correctly accounting for it in analyses all involve difficult decisions for the researcher. Our objectives were: to collate recommendations on the subject of dealing with heterogeneity in systematic reviews of clinical trials; to investigate current practice in addressing heterogeneity in Cochrane reviews; and to compare current practice with recommendations. Methods: We review guidelines for those undertaking systematic reviews and examine how heterogeneity is addressed in practice in a sample of systematic reviews, and their protocols, from the Cochrane Database of Systematic Reviews. Results: Advice to reviewers is on the whole consistent and sensible. However, examination of a sample of Cochrane protocols and reviews demonstrates that the advice is difficult to follow given the small numbers of studies identified in many systematic reviews, the difficulty of pre-specifying important effect modifiers for subgroup analysis or meta-regression and the unresolved debate concerning fixed versus random effects metaanalyses. There was disagreement between protocols and reviews, often either regarding choice of important potential effect modifiers or due to the review identifying too few studies to perform planned analyses. Conclusion: Guidelines that address practical issues are required to reduce the risk of spurious findings from investigations of heterogeneity. This may involve discouraging statistical investigations such as subgroup analyses and meta-regression, rather than simply adopting a cautious approach to their interpretation, unless a large number of studies is available. The notion of a priori specification of potential effect modifiers for a retrospective review of studies is ill-defined, and the appropriateness of using a statistical test for heterogeneity to decide between analysis strategies is suspect.

scholarly journals Low Methodological Quality of Systematic Reviews on Acupuncture: A Cross- Sectional Study

2021 ◽  
Author(s):  
Leonard TF Ho ◽  
Fiona YT Ke ◽  
Charlene HL Wong ◽  
Irene XY Wu ◽  
Andy KL Cheung ◽  
...  
Keyword(s):  
Systematic Reviews ◽  
Methodological Quality ◽  
Meta Analysis ◽  
A Priori ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Quality Ratings ◽  
Cochrane Reviews

Abstract Background: While well-conducted systematic reviews (SRs) can provide best evidence on the potential effectiveness of acupuncture, limitations on methodological rigour of SRs may impact trustworthiness of their conclusions. This cross-sectional study aimed to evaluate the methodological quality of a representative sample of SRs on acupuncture effectiveness.Methods: CDSR, MEDLINE, and EMBASE were searched for SRs on acupuncture. AMSTAR2 was applied for assessing methodological quality. Associations between bibliographical characteristics and methodological quality ratings were examined. Results: A total of 106 SRs were appraised. Only one (0.9%) SR was of high overall methodological quality, zero (0%) was of moderate-quality, six (5.7%) and 99 (93.4%) were of low-quality and critically low-quality respectively. Among appraised SRs, only ten (9.4%) provided an a priori protocol, four (3.8%) conducted a comprehensive literature search, five (4.7%) provided a list of excluded study, and six (5.7%) performed meta-analysis appropriately. Cochrane reviews, update reviews, reviews with corresponding authors from the America, and reviews that searched non-English databases had relatively higher overall quality. Conclusions: Methodological quality of SRs on acupuncture is unsatisfactory. Future reviewers should improve critical areas of publishing protocols, performing comprehensive search, providing a list of excluded studies with justifications for exclusion, and conducting meta-analysis appropriately.

scholarly journals Ranking videolaryngoscopes and direct laryngoscopes by orotracheal intubation performance in children: protocol of a systematic review and network meta-analysis of randomized clinical trials at patient level

2021 ◽  
Author(s):  
Clístenes C Carvalho ◽  
Stéphanie LPA Regueira ◽  
Ana Beatriz S Souza ◽  
Lucas MLF Medeiros ◽  
Marielle BS Manoel
Keyword(s):  
Systematic Review ◽  
Clinical Trials ◽  
Randomized Clinical Trials ◽  
Meta Analysis ◽  
A Priori ◽  
Orotracheal Intubation ◽  
Sensitivity Analyses ◽  
Intubation Attempt ◽  
Cochrane Central Register ◽  
Meta Regression

ABSTRACTBackgroundVideolaryngoscopy was shown to improve glottic visualization in children as compared to direct laryngoscopy, but at the expenses of delayed time for intubation. As little evidence is available regarding the relative performance of different laryngoscopes at present, we designed this systematic review and network meta-analysis to rank the different videolaryngoscopes (VLs) and direct laryngoscopes (DLs) for orotracheal intubation in children.MethodsWe will conduct a search in PubMed, LILACS, Scielo, Embase, Web of Science, and Cochrane Central Register of Controlled Trials (CENTRAL; 2021, Issue 1) on 27/01/2021. We will include randomized clinical trials fully reported with patients aged ≤ 18 years, making comparisons between different types of laryngoscopes (any of both VLs and DLs) for failed first intubation attempt, intubation time, number of attempts at intubation or number of unsuccessful intubations, failed intubation, glottic view score, or adverse responses to endotracheal intubation. Pooled effects will be estimated by both fixed and random-effects models and presented according to qualitative and quantitative heterogeneity assessment. Sensitivity analyses will be performed as well as a priori subgroup, meta-regression and multiple meta-regression analyses. Additionally, network meta-analyses will be applied to rank the different VLs and DLs. We will also assess the risk of selective publication by funnel plot asymmetry.DiscussionThis systematic review and network meta-analysis aim to understand which laryngoscopes perform better than others for orotracheal intubation.Systematic review registrationThe current protocol was submitted to PROSPERO on 25/01/2021.

scholarly journals Ranking videolaryngoscopes by orotracheal intubation performance: protocol of a systematic review and network meta-analysis of clinical trials at patient level

2021 ◽  
Author(s):  
Clístenes Crístian de Carvalho ◽  
Danielle Melo da Silva ◽  
Victor Macedo Lemos ◽  
Thiago Gadelha Batista dos Santos ◽  
Ikaro Cavalcante Agra ◽  
...  
Keyword(s):  
Systematic Review ◽  
Clinical Trials ◽  
Randomized Clinical Trials ◽  
Meta Analysis ◽  
A Priori ◽  
Macintosh Laryngoscope ◽  
Orotracheal Intubation ◽  
Sensitivity Analyses ◽  
Cochrane Central Register ◽  
Meta Regression

ABSTRACTBackgroundVideolaryngoscopes (VLs) are regarded to improve glottic visualization as compared to Macintosh laryngoscope (ML). However, we currently do not know which one would be the best choice. We then designed this systematic review and network meta-analysis to rank the different VLs as compared to ML.MethodsWe will conduct a search in PubMed, LILACS, Scielo, Embase, Web of Science, and Cochrane Central Register of Controlled Trials (CENTRAL; 2020, Issue 6) on 11/01/2021. We will include randomized clinical trials fully reported with patients aged ≥ 16 years, comparing VLs with ML for failed intubation with the device, failed first intubation attempts, number of intubation attempts, time for intubation, difficulty of intubation, and improved visualization of the larynx. Pooled effects will be estimated by both fixed and random-effects models and presented according to qualitative and quantitative heterogeneity assessment. Sensitivity analyses will be performed as well as a priori subgroup, meta-regression and multiple meta-regression analyses. Additionally, network meta-analyses will be applied to rank the different VLs as compared to ML. We will also assess the risk of selective publication by funnel plot asymmetry.DiscussionThis systematic review and network meta-analysis aim at helping health services and clinicians involved in airway manipulation choose the best VLs for orotracheal intubation.Systematic review registrationThe current protocol was submitted to PROSPERO on 07/01/2021.

Effects of diacerein intake on cardiometabolic profiles in type 2 diabetics: a systematic review and meta-analysis of clinical trials.

2020 ◽  
Vol 27 ◽  
Author(s):  
Peyman Nowrouzi-Sohrabi ◽  
Reza Tabrizi ◽  
Mohammad Jalali ◽  
Navid Jamali ◽  
Shahla Rezaei ◽  
...  
Keyword(s):  
Systematic Review ◽  
Clinical Trials ◽  
Body Weight ◽  
Total Cholesterol ◽  
Ldl Cholesterol ◽  
Meta Analysis ◽  
Hdl Cholesterol ◽  
Cochrane Central Register ◽  
Statistical Heterogeneity

Introduction: A systematic review and meta-analysis of clinical trials was undertaken to evaluate the effect of diacerein intake on cardiometabolic profiles in patients with type 2 diabetes mellitus (T2DM). Methods: Electronic databases such as PubMed, EMBASE, Scopus, Web of Science, Google Scholar, and Cochrane Central Register of Controlled Trials were searched from inception to 31 July 2019. Statistical heterogeneity was evaluated using Cochran’s Q test and I-square (I2 ) statistic. Data were pooled using random-effect models and weighted mean difference (WMD). Results: From 1,733 citations, seven clinical trials were eligible for inclusion and meta-analysis. A significant reduction in hemoglobin A1c (HbA1c) (WMD -0.73; 95%CI -1.25 to -0.21; P= 0.006; I2 = 72.2%) and body mass index (BMI) (WMD -0.55; 95%CI -1.03 to -0.07; P= 0.026; I2 = 9.5%) were identified. However, no significant effect of diacerein intake was identified on fasting blood sugar (FBS) (WMD - 9.00; 95%CI -22.57 to 4.57; P= 0.194; I2 = 60.5%), homeostatic model assessment for insulin resistance (HOMA-IR) (WMD 0.39; 95%CI 0.95 to 1.73; P= 0.569; I2 = 2.2%), body weight (WMD -0.54; 95%CI -1.10 to 0.02; P= 0.059), triglycerides (WMD -0.56; 95%CI -24.16 to 23.03; P= 0.963; I2 = 0.0%), total-cholesterol (WMD -0.21; 95%CI -12.19 to 11.78; P= 0.973; I2 = 0.0%), HDL-cholesterol (WMD -0.96; 95%CI -2.85 to 0.93; P= 0.321; I2 = 0.0%), and LDL-cholesterol levels (WMD -0.09; 95%CI -8.43 to 8.25; P= 0.983; I2 = 37.8%). Conclusion: Diacerein intake may reduce HbA1c and BMI; however, no evidence of effect was observed for FBS, HOMA-IR, body weight, triglycerides, total-cholesterol, HDL-cholesterol or LDL-cholesterol.

scholarly journals Random-effects meta-analysis for systematic reviews of phase I clinical trials: Rare events and missing data

2016 ◽  
Vol 8 (2) ◽  
pp. 124-135 ◽  
Author(s):  
Mi-Ok Kim ◽  
Xia Wang ◽  
Chunyan Liu ◽  
Kathleen Dorris ◽  
Maryam Fouladi ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Missing Data ◽  
Phase I ◽  
Random Effects ◽  
Systematic Reviews ◽  
Rare Events ◽  
Meta Analysis ◽  
Phase I Clinical Trials

PERFIL DOS USUÁRIOS DE TERAPIA NUTRICIONAL PARENTERAL EM HOSPITAIS NO CENÁRIO BRASILEIRO: UMA REVISÃO SISTEMÁTICA DE LITERATURA

2021 ◽  
Vol 2 (9) ◽  
pp. e29688
Author(s):  
Jerônimo Gregório da Silva Neto ◽  
Ana Lourdes dos Reis Silva ◽  
Bruna Rayelle Freitas Lira ◽  
Maria Eduarda Pereira Alves ◽  
Amanda Cristine Ferreira dos Santos
Keyword(s):  
Systematic Reviews ◽  
Meta Analysis ◽  
A Priori ◽  
Electronic Library ◽  
Nrs 2002

A Terapia Nutricional são procedimentos terapêuticos realizados nos pacientes incapazes de satisfazer adequadamente suas necessidades nutricionais e metabólicas por via oral. Esse conjunto de procedimentos visa à manutenção ou recuperação do paciente em estado nutricional por meio da Nutrição Parenteral (NP) ou Enteral (NE). Investigar o perfil dos pacientes submetidos à Terapia Nutricional Parenteral (TNP) em hospitais brasileiros.  Trata-se de uma revisão sistemática realizada seguindo as recomendações PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis). Realizou-se busca para seleção dos estudos em cinco bases de dados: Literatura Latino-Americana em Ciências da Saúde (LILACS), Scientific Electronic, Library Online (SciELO) e Medline, usando os descritores de busca: “Terapia Nutricional”, “Nutrição Parenteral” e “Brasil”, por meio dos operadores boleanos “and” e “or”. Os critérios de inclusão foram: artigos originais, relacionados ao tema de interesse desse estudo e publicados nos últimos cinco anos (2015-2020) nos idiomas português e inglês. Por meio da investigação nas bases de dados foram encontrados 57 artigos, desses foram selecionados 43 dos últimos 5 anos, dos quais 2 eram duplicados e 12 não atendiam aos critérios de inclusão estabelecidos à priori, resultando em 14 artigos. Verificou-se risco de desnutrição de acordo com NRS-2002 e alto risco de desnutrição de acordo com 'MUST' aumentaram os custos do paciente, respectivamente, em 21,1% e 28,8%. A terapia nutricional parenteral retrata uma parte importante dos custos no tratamento de indivíduos hospitalizados, principalmente nos casos de cânceres. De acordo com os dados analisados o custo com dieta parenteral foi maior no grupo de óbitos.  

Research Protocol for Systematic Review and Meta-Analysis of Elder Abuse Prevalence Studies

2017 ◽  
Vol 36 (2) ◽  
pp. 256-265 ◽  
Author(s):  
Yongjie Yon ◽  
Christopher Mikton ◽  
Zachary D. Gassoumis ◽  
Kathleen H. Wilber
Keyword(s):  
Systematic Review ◽  
Systematic Reviews ◽  
Elder Abuse ◽  
Meta Analysis ◽  
Personnes Âgées ◽  
Nous Allons ◽  
Research Protocol ◽  
Prevalence Studies ◽  
Revue Systématique ◽  
Meta Regression

RÉSUMÉLa maltraitance des personnes âgées est un important problème de santé publique et de droits de l’homme. Néanmoins, notre connaissance de la veritable ampleur du phénomène demeure limitée. Pour y remédier, nous allons procéder à une revue systématique et une méta-analyse des études de prevalence de la maltraitance des personnes âgées dans le monde entier. Ce protocole décrit l’approche méthodologique qui sera adoptée pour la réalisation de la revue systématique et de la méta-analyse. En particulier, le protocole décrit le développement des stratégies de recherche et des critères pour identifier et sélectionner les études de prévalence ainsi que la façon dont les données des études sélectionnées seront extraites pour l’analyse. Le protocole décrit également l’approche analytique qui sera utilisée pour calculer les estimations de prevalence et l’utilisation de méta-régression pour évaluer la façon dont les caractéristiques des études influencent les estimations de la prévalence. Ce protocole est conforme au “Preferred Reporting Items for Systematic reviews and Meta-Analysis” – ou PRISMA – et a été enregistré auprès du registre de revues systématique PROSPERO International Prospective Register.

scholarly journals The use of ‘PICO for synthesis’ and methods for synthesis without meta-analysis: protocol for a survey of current practice in systematic reviews of health interventions

F1000Research ◽  
2021 ◽  
Vol 9 ◽  
pp. 678
Author(s):  
Miranda S. Cumpston ◽  
Joanne E. McKenzie ◽  
James Thomas ◽  
Sue E. Brennan
Keyword(s):  
Health Systems ◽  
Systematic Reviews ◽  
Current Practice ◽  
Meta Analysis ◽  
Visual Display ◽  
Health Interventions ◽  
Synthesis Process ◽  
Future Research ◽  
Synthesis Methods ◽  
Definition Of

Introduction: Systematic reviews involve synthesis of research to inform decision making by clinicians, consumers, policy makers and researchers. While guidance for synthesis often focuses on meta-analysis, synthesis begins with specifying the ’PICO for each synthesis’ (i.e. the criteria for deciding which populations, interventions, comparators and outcomes are eligible for each analysis). Synthesis may also involve the use of statistical methods other than meta-analysis (e.g. vote counting based on the direction of effect, presenting the range of effects, combining P values) augmented by visual display, tables and text-based summaries. This study examines these two aspects of synthesis. Objectives: To identify and describe current practice in systematic reviews of health interventions in relation to: (i) approaches to grouping and definition of PICO characteristics for synthesis; and (ii) methods of summary and synthesis when meta-analysis is not used. Methods: We will randomly sample 100 systematic reviews of the quantitative effects of public health and health systems interventions published in 2018 and indexed in the Health Evidence and Health Systems Evidence databases. Two authors will independently screen citations for eligibility. Two authors will confirm eligibility based on full text, then extract data for 20% of reviews on the specification and use of PICO for synthesis, and the presentation and synthesis methods used (e.g. statistical synthesis methods, tabulation, visual displays, structured summary). The remaining reviews will be confirmed as eligible and data extracted by a single author. We will use descriptive statistics to summarise the specification of methods and their use in practice. We will compare how clearly the PICO for synthesis is specified in reviews that primarily use meta-analysis and those that do not. Conclusion: This study will provide an understanding of current practice in two important aspects of the synthesis process, enabling future research to test the feasibility and impact of different approaches.

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