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European Journal of Epidemiology Jan 2020To inform evidence-based practice in health care, guidelines and policies require accurate identification, collation, and integration of all available evidence in a...
To inform evidence-based practice in health care, guidelines and policies require accurate identification, collation, and integration of all available evidence in a comprehensive, meaningful, and time-efficient manner. Approaches to evidence synthesis such as carefully conducted systematic reviews and meta-analyses are essential tools to summarize specific topics. Unfortunately, not all systematic reviews are truly systematic, and their quality can vary substantially. Since well-conducted evidence synthesis typically involves a complex set of steps, we believe formulating a cohesive, step-by-step guide on how to conduct a systemic review and meta-analysis is essential. While most of the guidelines on systematic reviews focus on how to report or appraise systematic reviews, they lack guidance on how to synthesize evidence efficiently. To facilitate the design and development of evidence syntheses, we provide a clear and concise, 24-step guide on how to perform a systematic review and meta-analysis of observational studies and clinical trials. We describe each step, illustrate it with concrete examples, and provide relevant references for further guidance. The 24-step guide (1) simplifies the methodology of conducting a systematic review, (2) provides healthcare professionals and researchers with methodologically sound tools for conducting systematic reviews and meta-analyses, and (3) it can enhance the quality of existing evidence synthesis efforts. This guide will help its readers to better understand the complexity of the process, appraise the quality of published systematic reviews, and better comprehend (and use) evidence from medical literature.
Topics: Humans; Guidelines as Topic; Meta-Analysis as Topic; Systematic Reviews as Topic
PubMed: 31720912
DOI: 10.1007/s10654-019-00576-5 -
Journal of Periodontology Jan 2021The peri-implant soft tissue phenotype (PSP) encompasses the keratinized mucosa width (KMW), mucosal thickness (MT), and supracrestal tissue height (STH). Numerous... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The peri-implant soft tissue phenotype (PSP) encompasses the keratinized mucosa width (KMW), mucosal thickness (MT), and supracrestal tissue height (STH). Numerous approaches to augment soft tissue volume around endosseous dental implants have been investigated. To what extent PSP modification is beneficial for peri-implant health has been subject of debate in the field of implant dentistry. The aim of this systematic review was to analyze the evidence regarding the efficacy of soft tissue augmentation procedures aimed at modifying the PSP and their impact on peri-implant health.
METHODS
A comprehensive search was performed to identify clinical studies that involved soft tissue augmentation around dental implants and reported findings on KMW, MT, and/or STH changes. The effect of the intervention on peri-implant health was also assessed. Selected articles were classified based on the general type of surgical approach to increase PSP, either bilaminar or an apically positioned flap (APF) technique. A network meta-analysis including only randomized-controlled trials (RCTs) reporting on PSP outcomes was conducted to assess and compare different techniques.
RESULTS
A total of 52 articles were included in the qualitative analysis, and 23 RCTs were included as part of the network meta-analysis. Sixteen RCTs reported the outcomes of PSP modification therapy with bilaminar techniques, whereas 7 involved the use of APF. The analysis showed that bilaminar techniques in combination with soft tissue grafts (connective tissue graft [CTG], collagen matrix [CM], and acellular dermal matrix [ADM]) resulted in a significant increase in MT compared to non-augmented sites. In particular, CTG and ADM were associated with higher MT gain as compared to CM and non-augmented sites. However, no significant differences in KMW were observed across different bilaminar techniques. PSP modification via a bilaminar approach utilizing either CTG or CM showed beneficial effects on marginal bone level stability. APF-based approaches in combination with free gingival graft (FGG), CTG, CM, or ADM showed a significant KMW gain compared to non-augmented sites. However, compared to APF alone, only FGG exhibited a significantly higher KMW gain. APF with any evaluated soft tissue graft was associated with with reduction of probing depth, soft tissue dehiscence and plaque index compared to non-augmented sites compared to non-augmented sites. The evidence regarding the effect of PSP modification via APF-based approaches on peri-implant marginal bone loss or preservation is inconclusive.
CONCLUSIONS
Bilaminar approach involving CTG or ADM obtained the highest amount of MT gain, whereas APF in combination with FGG was the most effective technique for increasing KMW. KMW augmentation via APF was associated with a significant reduction in probing depth, soft tissue dehiscence and plaque index, regardless of the soft tissue grafting material employed, whereas bilaminar techniques with CTG or CM showed beneficial effects on marginal bone level stability.
Topics: Connective Tissue; Dental Implants; Gingiva; Network Meta-Analysis; Phenotype
PubMed: 32710810
DOI: 10.1002/JPER.19-0716 -
Neuroscience and Biobehavioral Reviews Sep 2021Misconceptions about ADHD stigmatize affected people, reduce credibility of providers, and prevent/delay treatment. To challenge misconceptions, we curated findings with... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Misconceptions about ADHD stigmatize affected people, reduce credibility of providers, and prevent/delay treatment. To challenge misconceptions, we curated findings with strong evidence base.
METHODS
We reviewed studies with more than 2000 participants or meta-analyses from five or more studies or 2000 or more participants. We excluded meta-analyses that did not assess publication bias, except for meta-analyses of prevalence. For network meta-analyses we required comparison adjusted funnel plots. We excluded treatment studies with waiting-list or treatment as usual controls. From this literature, we extracted evidence-based assertions about the disorder.
RESULTS
We generated 208 empirically supported statements about ADHD. The status of the included statements as empirically supported is approved by 80 authors from 27 countries and 6 continents. The contents of the manuscript are endorsed by 366 people who have read this document and agree with its contents.
CONCLUSIONS
Many findings in ADHD are supported by meta-analysis. These allow for firm statements about the nature, course, outcome causes, and treatments for disorders that are useful for reducing misconceptions and stigma.
Topics: Attention Deficit Disorder with Hyperactivity; Humans; Network Meta-Analysis; Publication Bias
PubMed: 33549739
DOI: 10.1016/j.neubiorev.2021.01.022 -
Evidence-based Mental Health Nov 2019Meta-analysis is of fundamental importance to obtain an unbiased assessment of the available evidence. In general, the use of meta-analysis has been increasing over the...
OBJECTIVE
Meta-analysis is of fundamental importance to obtain an unbiased assessment of the available evidence. In general, the use of meta-analysis has been increasing over the last three decades with mental health as a major research topic. It is then essential to well understand its methodology and interpret its results. In this publication, we describe how to perform a meta-analysis with the freely available statistical software environment R, using a working example taken from the field of mental health.
METHODS
R package meta is used to conduct standard meta-analysis. Sensitivity analyses for missing binary outcome data and potential selection bias are conducted with R package metasens. All essential R commands are provided and clearly described to conduct and report analyses.
RESULTS
The working example considers a binary outcome: we show how to conduct a fixed effect and random effects meta-analysis and subgroup analysis, produce a forest and funnel plot and to test and adjust for funnel plot asymmetry. All these steps work similar for other outcome types.
CONCLUSIONS
R represents a powerful and flexible tool to conduct meta-analyses. This publication gives a brief glimpse into the topic and provides directions to more advanced meta-analysis methods available in R.
Topics: Biomedical Research; Humans; Meta-Analysis as Topic; Software
PubMed: 31563865
DOI: 10.1136/ebmental-2019-300117 -
The International Journal on Drug Policy Nov 2021This study aimed to determine the efficacy and acceptability of pharmacotherapies for cannabis use disorder (CUD). (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
This study aimed to determine the efficacy and acceptability of pharmacotherapies for cannabis use disorder (CUD).
METHODS
We conducted a systematic review and frequentist network meta-analysis, searching five electronic databases for randomized placebo-controlled trials of individuals diagnosed with CUD receiving pharmacotherapy with or without concomitant psychotherapy. Primary outcomes were the reduction in cannabis use and retention in treatment. Secondary outcomes were adverse events, discontinuation due to adverse events, total abstinence, withdrawal symptoms, cravings, and CUD severity. We applied a frequentist, random-effects Network Meta-Analysis model to pool effect sizes across trials using standardized mean differences (SMD, g) and rate ratios (RR) with their 95% confidence intervals.
RESULTS
We identified a total of 24 trials (n=1912, 74.9% male, mean age 30.2 years). Nabilone (d=-4.47 [-8.15; -0.79]), topiramate (d=-3.80 [-7.06; -0.54]), and fatty-acid amyl hydroxylase inhibitors (d=-2.30 [-4.75; 0.15]) reduced cannabis use relative to placebo. Dronabinol improved retention in treatment (RR=1.27 [1.02; 1.57]), while topiramate worsened treatment retention (RR=0.62 [0.42; 0.91]). Gabapentin reduced cannabis cravings (d=-2.42 [-3.53; -1.32], while vilazodone worsened craving severity (d=1.69 [0.71; 2.66]. Buspirone (RR=1.14 [1.00; 1.29]), venlafaxine (RR=1.78 [1.40; 2.26]), and topiramate (RR=9.10 [1.27; 65.11]) caused more adverse events, while topiramate caused more dropouts due to adverse events.
CONCLUSIONS
Based on this review, some medications appeared to show promise for treating individual aspects of CUD. However, there is a lack of robust evidence to support any particular pharmacological treatment. There is a need for additional studies to expand the evidence base for CUD pharmacotherapy. While medication strategies may become an integral component for CUD treatment one day, psychosocial interventions should remain the first line given the limitations in the available evidence.
Topics: Adult; Female; Humans; Male; Marijuana Abuse; Network Meta-Analysis
PubMed: 34062288
DOI: 10.1016/j.drugpo.2021.103295 -
Ageing Research Reviews Apr 2022To examine the dose-response relationship between overall and specific types of exercise with cognitive function in older adults. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To examine the dose-response relationship between overall and specific types of exercise with cognitive function in older adults.
DESIGN
Systematic Review and Bayesian Model-Based Network Meta-Analysis.
DATA SOURCES
Systematic search of MEDLINE, Web of Science, Scopus, PsycINFO and SPORTDiscus.
ELIGIBILITY CRITERIA FOR SELECTING STUDIES
Randomized controlled trials of exercise interventions in participants aged 50 years or over, and that reported on at least one global cognition outcome.
RESULTS
The search returned 1998 records, of which 44 studies (4793 participants; 102 different effect sizes) were included in this review with meta-analysis. There was a non-linear, dose-response association between overall exercise and cognition. We found no minimal threshold for the beneficial effect of exercise on cognition. The estimated minimal exercise dose associated with clinically relevant changes in cognition was 724 METs-min per week, and doses beyond 1200 METs-min per week provided less clear benefits. We also found that the dose-response association was exercise type dependent, and our results show that clinically important effects may occur at lower doses for many types of exercise. Our findings also highlighted the superior effects of resistance exercises over other modalities.
CONCLUSIONS
If provided with the most potent modalities, older adults can get clinical meaningful benefits with lower doses than the WHO guidelines. Findings support the WHO recommendations to emphasise resistance training as a critical component of interventions for older adults.
Topics: Aged; Bayes Theorem; Cognition; Exercise; Exercise Therapy; Humans; Network Meta-Analysis
PubMed: 35182742
DOI: 10.1016/j.arr.2022.101591 -
Indian Pediatrics Apr 2022Systematic reviews involve the application of scientific methods to reduce bias in review of literature. The key components of a systematic review are a well-defined... (Meta-Analysis)
Meta-Analysis
Systematic reviews involve the application of scientific methods to reduce bias in review of literature. The key components of a systematic review are a well-defined research question, comprehensive literature search to identify all studies that potentially address the question, systematic assembly of the studies that answer the question, critical appraisal of the methodological quality of the included studies, data extraction and analysis (with and without statistics), and considerations towards applicability of the evidence generated in a systematic review. These key features can be remembered as six 'A'; Ask, Access, Assimilate, Appraise, Analyze and Apply. Meta-analysis is a statistical tool that provides pooled estimates of effect from the data extracted from individual studies in the systematic review. The graphical output of meta-analysis is a forest plot which provides information on individual studies and the pooled effect. Systematic reviews of literature can be undertaken for all types of questions, and all types of study designs. This article highlights the key features of systematic reviews, and is designed to help readers understand and interpret them. It can also help to serve as a beginner's guide for both users and producers of systematic reviews and to appreciate some of the methodological issues.
Topics: Humans; Meta-Analysis as Topic; Research Design; Systematic Reviews as Topic
PubMed: 34183469
DOI: 10.1007/s13312-022-2500-y -
BioMed Research International 2022This study is aimed at performing a systematic review and a network meta-analysis of the effects of several membranes on vertical bone regeneration and clinical... (Meta-Analysis)
Meta-Analysis Review
This study is aimed at performing a systematic review and a network meta-analysis of the effects of several membranes on vertical bone regeneration and clinical complications in guided bone regeneration (GBR) or guided tissue regeneration (GTR). We compared the effects of the following membranes: high-density polytetrafluoroethylene (d-PTFE), expanded polytetrafluoroethylene (e-PTFE), crosslinked collagen membrane (CCM), noncrosslinked collagen membrane (CM), titanium mesh (TM), titanium mesh plus noncrosslinked (TM + CM), titanium mesh plus crosslinked (TM + CCM), titanium-reinforced d-PTFE, titanium-reinforced e-PTFE, polylactic acid (PLA), polyethylene glycol (PEG), and polylactic acid 910 (PLA910). Using the PICOS principles to help determine inclusion criteria, articles are collected using PubMed, Web of Science, and other databases. Assess the risk of deviation and the quality of evidence using the Cochrane Evaluation Manual, and GRADE. 27 articles were finally included. 19 articles were included in a network meta-analysis with vertical bone increment as an outcome measure. The network meta-analysis includes network diagrams, paired-comparison forest diagrams, funnel diagrams, surface under the cumulative ranking curve (SUCRA) diagrams, and sensitivity analysis diagrams. SUCRA indicated that titanium-reinforced d-PTFE exhibited the highest vertical bone increment effect. Meanwhile, we analyzed the complications of 19 studies and found that soft tissue injury and membrane exposure were the most common complications.
Topics: Bone Regeneration; Collagen; Guided Tissue Regeneration, Periodontal; Membranes, Artificial; Network Meta-Analysis; Polytetrafluoroethylene; Titanium
PubMed: 35872861
DOI: 10.1155/2022/7742687 -
Medicina (Kaunas, Lithuania) Jun 2022To compare the efficacy and safety of topical interventions used for recurrent aphthous stomatitis. This network meta-analysis was conducted in accordance with the... (Meta-Analysis)
Meta-Analysis Review
To compare the efficacy and safety of topical interventions used for recurrent aphthous stomatitis. This network meta-analysis was conducted in accordance with the PRISMA statement. We searched four electronic databases, PubMed, Web of Science (WOS), Cochrane Central Register of Controlled Trials and Embase, for randomized controlled trials reporting efficacy and safety data on topical interventions for recurrent aphthous stomatitis. We performed a quality evaluation using a methodology based on the Cochrane Handbook. Two authors independently extracted data on healing effect, size reduction effect, symptom reduction effect, recurrence and safety assessment. Network meta-analysis was then performed using ADDIS and RevMan. : A total of 72 trials (5272 subjects) involving 29 topical interventions were included. Honey, lnsulin liposome gel, laser, amlexanox, glycyrrhiza and triamcinolone had better efficacy performance. Probiotics and chlorhexidine helped to prolong ulcer intervals and reduce recurrence. Doxycycline and penicillin had a high risk of adverse events. Hematologic evaluation showed no preference. The rank possibility of size-reducing effect and symptom-reducing effect supported the short-term effect of laser and the long-term effect of probiotics. : We recommend the use of laser as a short-term intervention during the exacerbation phase of RAS and probiotics as a long-term intervention during the exacerbation and remission phases of RAS.
Topics: Humans; Network Meta-Analysis; Stomatitis, Aphthous; Wound Healing
PubMed: 35744034
DOI: 10.3390/medicina58060771 -
Journal of Personality and Social... Sep 2019Using a novel technique known as network meta-analysis, we synthesized evidence from 492 studies (87,418 participants) to investigate the effectiveness of procedures in... (Meta-Analysis)
Meta-Analysis
Using a novel technique known as network meta-analysis, we synthesized evidence from 492 studies (87,418 participants) to investigate the effectiveness of procedures in changing implicit measures, which we define as response biases on implicit tasks. We also evaluated these procedures' effects on explicit and behavioral measures. We found that implicit measures can be changed, but effects are often relatively weak (|s| < .30). Most studies focused on producing short-term changes with brief, single-session manipulations. Procedures that associate sets of concepts, invoke goals or motivations, or tax mental resources changed implicit measures the most, whereas procedures that induced threat, affirmation, or specific moods/emotions changed implicit measures the least. Bias tests suggested that implicit effects could be inflated relative to their true population values. Procedures changed explicit measures less consistently and to a smaller degree than implicit measures and generally produced trivial changes in behavior. Finally, changes in implicit measures did not mediate changes in explicit measures or behavior. Our findings suggest that changes in implicit measures are possible, but those changes do not necessarily translate into changes in explicit measures or behavior. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
Topics: Humans; Network Meta-Analysis; Psychological Tests; Psychology, Social; Social Perception
PubMed: 31192631
DOI: 10.1037/pspa0000160