scholarly journals Evidence-based umbrella review of cognitive effects of prefrontal tDCS

Author(s):  
Luis C Farhat ◽  
Andre F Carvalho ◽  
Marco Solmi ◽  
Andre R Brunoni

Abstract Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique, which has been increasingly used as an investigational tool in neuroscience. In social and affective neuroscience research, the prefrontal cortex has been primarily targeted, since this brain region is critically involved in complex psychobiological processes subserving both ‘hot’ and ‘cold’ domains. Although several studies have suggested that prefrontal tDCS can enhance neuropsychological outcomes, meta-analyses have reported conflicting results. Therefore, we aimed to assess the available evidence by performing an umbrella review of meta-analyses. We evaluated the effects of prefrontal active vs sham tDCS on different domains of cognition among healthy and neuropsychiatric individuals. A MeaSurement Tool to Assess Systematic Reviews 2 was employed to evaluate the quality of meta-analyses, and the GRADE system was employed to grade the quality of evidence of every comparison from each meta-analysis. PubMed/MEDLINE, PsycINFO and the Cochrane Database of Systematic Reviews were searched, and 11 meta-analyses were included resulting in 55 comparisons. Only 16 comparisons reported significant effects favoring tDCS, but 13 of them had either very low or low quality of evidence. Of the remaining 39 comparisons which reported non-significant effects, 38 had either very low or low quality of evidence. Meta-analyses were rated as having critically low and low quality. Among several reasons to explain these findings, the lack of consensus and reproducibility in tDCS research is discussed.

BMJ Open ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. e053851
Author(s):  
Karem Slim ◽  
Flora Badon ◽  
Charles-Hervé Vacheron ◽  
Chadli Dziri ◽  
Thomas Marquillier

IntroductionImmunonutrition (IN) is generally used before major visceral surgery with the intent to reduce postoperative complications, especially infectious ones. However, the conclusions of published meta-analyses are conflicting. The purpose of this review is to synthesise the data of published systematic reviews on the effectiveness of IN.Methods and analysisThis protocol follows the Preferred Reporting Items for Systematic Reviews and Meta-analyses Protocols guidelines. This is an umbrella review of systematic reviews comparing IN (delivered orally 5–7 days preoperatively) with normal diet or isocaloric isonitrogenous feeding before visceral surgery performed on any of several viscera (colorectum, stomach, pancreas, liver, oesophagus). We search the systematic reviews included in the main bibliographic databases. To assess the efficacy of IN, several outcomes will be considered: the main outcome is infectious complications (surgical site infections, pulmonary infections or urinary infections) and secondary outcomes are overall morbidity, hospital length of stay and mortality. Identified reviews will be screened by two independent assessors. The methodological quality of relevant included reviews will be assessed using A MeaSurement Tool to Assess systematic Reviews (AMSTAR) instrument. The data extracted from included reviews will be synthesised using the r-Metafor package considering separate groups according to the viscus of interest. Publication bias will be evaluated, and subgroup analyses will be performed according to the quality of studies and preoperative nutritional status.Ethics and disseminationAn umbrella review based on published data from systematic reviews needs no ethical approval. Furthermore, no patient will be involved in the review. Once terminated, the review will be submitted for publication in an open access journal to ensure wide dissemination of the findings.PROSPERO registration numberCRD42021255177.


2020 ◽  
pp. 219256822090681 ◽  
Author(s):  
Muthu Sathish ◽  
Ramakrishnan Eswar

Study Design: Systematic review. Objectives: To assess the methodological quality of systematic reviews and meta-analyses in spine surgery over the past 2 decades. Materials and Methods: We conducted independent and in duplicate systematic review of the published systematic reviews and meta-analyses between 2000 and 2019 from PubMed Central and Cochrane Database pertaining to spine surgery involving surgical intervention. We searched bibliographies to identify additional relevant studies. Methodological quality was evaluated with AMSTAR score and graded with AMSTAR 2 criteria. Results: A total of 96 reviews met the eligibility criteria, with mean AMSTAR score of 7.51 (SD = 1.98). Based on AMSTAR 2 criteria, 13.5% (n = 13) and 18.7% (n = 18) of the studies had high and moderate level of confidence of results, respectively, without any critical flaws. A total of 29.1% (n = 28) of the studies had at least 1 critical flaw and 38.5% (n = 37) of the studies had more than 1 critical flaw, so that their results have low and critically low confidence, respectively. Failure to analyze the conflict of interest of authors of primary studies included in review and lack of list of excluded studies with justification were the most common critical flaw. Regression analysis demonstrated that studies with funding and studies published in recent years were significantly associated with higher methodological quality. Conclusion: Despite improvement in methodological quality of systematic reviews and meta-analyses in spine surgery in current decade, a substantial proportion continue to show critical flaws. With increasing number of review articles in spine surgery, stringent measures must be taken to adhere to methodological quality by following PRISMA and AMSTAR guidelines to attain higher standards of evidence in published literature.


Author(s):  
Svjetlana Dosenovic ◽  
Andria Dujmic ◽  
Danijela Nujic ◽  
Ivana Vuka ◽  
Goran Tintor ◽  
...  

Aim: Systematic reviews (SRs) are frequently inconclusive. The aim of this study was to analyze factors associated with conclusiveness of SRs about efficacy and safety of interventions for neuropathic pain (NeuP). Materials & methods: The study protocol was registered in the PROSPERO database (No. CRD42015025831). Five electronic databases (Medical Literature Analysis and Retrieval System Online, Cochrane Database of Systematic Reviews, Cumulative Index for Nursing and Allied Health Literature, Database of Abstracts of Reviews of Effects and Psychological Information Database) were searched until July 2018 for SRs about NeuP management. Conclusion statements for efficacy and safety, and characteristics of SRs were analyzed. Conclusiveness was defined as explicit statement by the SR authors that one intervention is better/similar to the other in terms of efficacy and safety. Methodological quality of SRs was assessed with the AMSTAR (A MeaSurement Tool to Assess systematic Reviews) tool. Results: Of 160 SRs, 37 (23%) were conclusive for efficacy and/or safety. In the SRs, conclusions about safety were missing in half of the analyzed abstracts, and a third of the full texts. Conclusive SRs included significantly more trials and participants, searched more databases, had more authors, conducted meta-analysis, analyzed quality of evidence, and had lower methodological quality than inconclusive SRs. The most common reasons for the lack of conclusiveness indicated by the SR authors were the small number of participants and trials, and the high heterogeneity of included studies. Conclusion: Most SRs about NeuP treatment were inconclusive. Sources of inconclusiveness of NeuP reviews need to be further studied, and SR authors need to provide conclusions about both safety and efficacy of interventions.


2021 ◽  
Vol 23 (Supplement_2) ◽  
pp. ii51-ii52
Author(s):  
A M George ◽  
S Gupta ◽  
S M Keshwara ◽  
M A Mustafa ◽  
C S Gillespie ◽  
...  

Abstract BACKGROUND Systematic reviews and meta-analyses constitute the highest level of research evidence and for a disease with limited clinical trial activity, are often relied upon to help inform clinical practice. This review of reviews evaluates both the reporting & methodological quality of meningioma evidence syntheses. MATERIAL AND METHODS Potentially eligible meningioma reviews published between 1st January 1990 and 31st December 2020 were identified from eight electronic databases. Inclusion required the study to meet the Cochrane guideline definition of a systematic review or meta-analysis. Reviews concerning neurofibromatosis type 2, spinal and pediatric meningiomas were excluded. The reporting and methodological quality of articles were assessed against the following modified guidelines: Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA), A MeaSurement Tool to Assess Systematic Reviews (AMSTAR2) and the Risk of Bias in Systematic Reviews (ROBIS) guidelines. RESULTS 117 systematic reviews were identified, 57 of which included meta-analysis (48.7%). The number of meningioma systematic reviews published each year has increased with 63 studies (53.9%) published between 01/2018 and 12/2020. A median of 17 studies (IQR 9–29) were included per review. Impact factor of journals publishing a systematic review with or without a meta-analysis was similar (median 2.3 vs 1.8, P=0.397). The mean PRISMA scores for systematic reviews with a meta-analysis was 21.11 (SD 4.1, 78% adherence) and without was 13.89 (SD 3.4, 63% adherence). Twenty-nine systematic reviews with meta-analysis (51%) and 11 without meta-analysis (18%) achieved greater than 80% adherence to PRISMA recommendations. Methodological quality assessment using AMSTAR2 revealed one study (0.9%) as high quality whilst 111 (94.8%) studies were graded as critically low. One hundred and two articles (87.2%) did not utilize a comprehensive search strategy as defined by the AMSTAR2 tool. Ninety-nine studies (84.6%) obtained a high level of concern for potential bias as per the ROBIS assessment. One hundred and eight articles (92.3%) failed to present information that a protocol had been established prior to study commencement and 76 articles (65.0%) did not conduct a risk of bias assessment. Across the three tools, domains relating to the establishment of a protocol prior to review commencement and conducting appropriate risk of bias assessments were frequently low scoring. CONCLUSION Overall reporting and methodological quality of meningioma systematic reviews was sub-optimal. Established critical appraisal tools and reporting guidelines should be utilized a priori to assist in producing high-quality systematic reviews.


2014 ◽  
Vol 133 (3) ◽  
pp. 206-217 ◽  
Author(s):  
Valter Silva ◽  
Antonio Jose Grande ◽  
Alan Pedrosa Viegas de Carvalho ◽  
Ana Luiza Cabrera Martimbianco ◽  
Rachel Riera

CONTEXT AND OBJECTIVE: Overviews of Systematic Reviews (OoRs) are a new type of study in which multiple evidence from systematic reviews (SRs) is compiled into an accessible and useful document. The aim here was to describe the state of the art and critically assess Cochrane OoRs that have been published.DESIGN AND SETTING: Descriptive study conducted at a research center.METHODS: The OoRs identified through the filter developed in Part I of this study were evaluated in five domains: methodological quality; quality of evidence; implications for practice; general profile of OoRs; and length of work.RESULTS: All 13 OoRs included had high methodological quality. Some OoRs did not present sufficient data to judge the quality of evidence; using sensitivity analysis, the quality of evidence of the OoRs increased. Regarding implications for practice, 64% of the interventions were judged as beneficial or harmful, while 36% of them showed insufficient evidence for judgment. It is expected (with 95% confidence interval) that one OoR will include 9,462 to 64,469 patients, 9 to 29 systematic reviews and 80 to 344 primary studies, and assess 6 to 21 interventions; and that 50 to 92% of OoRs will produce meta-analysis. The OoRs generated 2 to 26 meta-analyses over a period of 18 to 31 months.CONCLUSION: The OoRs presented high methodological quality; the quality of evidence tended to be moderate/high; most interventions were judged to be beneficial/harmful; the mean length of work was 24 months. The OoR profile adds power to decision-making.


2021 ◽  
pp. postgradmedj-2020-139392
Author(s):  
Rachel Wurth ◽  
Michelle Hajdenberg ◽  
Francisco J Barrera ◽  
Skand Shekhar ◽  
Caroline E Copacino ◽  
...  

AimThe aim of this study was to systematically appraise the quality of a sample of COVID-19-related systematic reviews (SRs) and discuss internal validity threats affecting the COVID-19 body of evidence.DesignWe conducted a scoping review of the literature. SRs with or without meta-analysis (MA) that evaluated clinical data, outcomes or treatments for patients with COVID-19 were included.Main outcome measuresWe extracted quality characteristics guided by A Measurement Tool to Assess Systematic Reviews-2 to calculate a qualitative score. Complementary evaluation of the most prominent published limitations affecting the COVID-19 body of evidence was performed.ResultsA total of 63 SRs were included. The majority were judged as a critically low methodological quality. Most of the studies were not guided by a pre-established protocol (39, 62%). More than half (39, 62%) failed to address risk of bias when interpreting their results. A comprehensive literature search strategy was reported in most SRs (54, 86%). Appropriate use of statistical methods was evident in nearly all SRs with MAs (39, 95%). Only 16 (33%) studies recognised heterogeneity in the definition of severe COVID-19 as a limitation of the study, and 15 (24%) recognised repeated patient populations as a limitation.ConclusionThe methodological and reporting quality of current COVID-19 SR is far from optimal. In addition, most of the current SRs fail to address relevant threats to their internal validity, including repeated patients and heterogeneity in the definition of severe COVID-19. Adherence to proper study design and peer-review practices must remain to mitigate current limitations.


2022 ◽  
pp. rapm-2021-102981
Author(s):  
Rachel H McGregor ◽  
Freda M Warner ◽  
Lukas D Linde ◽  
Jacquelyn J Cragg ◽  
Jill A Osborn ◽  
...  

BackgroundIn an attempt to aggregate observations from clinical trials, several meta-analyses have been published examining the effectiveness of systemic, non-opioid, pharmacological interventions to reduce the incidence of chronic postsurgical pain.ObjectiveTo inform the design and reporting of future studies, the purpose of our study was to examine the quality of these meta-analyses.Evidence reviewWe conducted an electronic literature search in Embase, MEDLINE, and the Cochrane Database of Systematic Reviews. Published meta-analyses, from the years 2010 to 2020, examining the effect of perioperative, systemic, non-opioid pharmacological treatments on the incidence of chronic postsurgical pain in adult patients were identified. Data extraction focused on methodological details. Meta-analysis quality was assessed using the A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2) critical appraisal tool.FindingsOur search yielded 17 published studies conducting 58 meta-analyses for gabapentinoids (gabapentin and pregabalin), ketamine, lidocaine, non-steroidal anti-inflammatory drugs, and mexiletine. According to AMSTAR 2, 88.2% of studies (or 15/17) were low or critically low in quality. The most common critical element missing was an analysis of publication bias. Trends indicated an improvement in quality over time and association with journal impact factor.ConclusionsWith few individual trials adequately powered to detect treatment effects, meta-analyses play a crucial role in informing the perioperative management of chronic postsurgical pain. In light of this inherent value and despite a number of attempts, high-quality meta-analyses are still needed.PROSPERO registration numberCRD42021230941.


2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Yu-Xi Li ◽  
Xi-li Xiao ◽  
Dong-Ling Zhong ◽  
Liao-Jun Luo ◽  
Han Yang ◽  
...  

Background. Migraine is a common neurological disease, which burdens individuals and society all over the world. Acupuncture, an important method in Traditional Chinese Medicine, is widely used in clinical practice as a treatment for migraine. Several systematic reviews (SRs) have investigated the effectiveness and safety of acupuncture for migraine. Objective. To summarize and critically assess the quality of relevant SRs and present an objective and comprehensive evidence on the effectiveness and safety of acupuncture for migraine. Data Sources. MEDLINE, Embase, Cochrane Library, PROSPERO database, Chinese National Knowledge Infrastructure (CNKI), Chinese Biological Medicine (CBM), China Science and Technology Journal (SCTJ), and WanFang database (WF) were searched from inception to December 2019 and grey literatures were manually searched. Selection Criteria. SRs which meet the criteria were independently selected by 2 reviewers according to a predetermined protocol. Data Extraction. Characteristics of included SRs were independently extracted by 2 reviewers following a predefined data extraction form. Review Appraisal. The methodological quality, risk of bias, and reporting quality of included SRs were assessed, respectively, by a Measurement Tool to Assess Systematic Reviews (AMSTAR) 2, the Risk of Bias in Systematic reviews (ROBIS) tool, and the Preferred Reporting Item for Systematic Review and Meta-analysis-Acupuncture (PRISMA-A) statement. The quality of outcomes was evaluated by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Results. A total of 15 SRs were included. All the SRs were published between 2011–2019. Based on AMSTAR 2, 14 out of 15 SRs were rated critically low quality and 1 was rated low quality. According to ROBIS tool, 9 SRs (60%) were low risk of bias. With the PRISMA-A checklist, we found 11 out of 15 SRs were found adequately reported over 70%. With the GRADE tool, we found high quality of evidence indicated that the effective rate of acupuncture was superior to western medicine in treatment of migraine. Besides, acupuncture reduced more headache days and the times of using painkiller and was more effective in reducing the frequency and degree of headache than western medicine and sham acupuncture. Limitations. There might be some missing information. The accuracy of the conclusions may be decreased reduced since we were unable to synthesis all the evidence. Conclusions. Based on high quality of evidence, we concluded that acupuncture may be an effective and safe therapy for migraine. However, the quality of SRs in acupuncture for migraine still needs more improvement.


2019 ◽  
Vol 54 (11) ◽  
pp. 681-688 ◽  
Author(s):  
Jozo Grgic ◽  
Ivana Grgic ◽  
Craig Pickering ◽  
Brad J Schoenfeld ◽  
David J Bishop ◽  
...  

ObjectiveTo systematically review, summarise and appraise findings of published meta-analyses that examined the effects of caffeine on exercise performance.DesignUmbrella review.Data sourcesTwelve databases.Eligibility criteria for selecting studiesMeta-analyses that examined the effects of caffeine ingestion on exercise performance.ResultsEleven reviews (with a total of 21 meta-analyses) were included, all being of moderate or high methodological quality (assessed using the Assessing the Methodological Quality of Systematic Reviews 2 checklist). In the meta-analyses, caffeine was ergogenic for aerobic endurance, muscle strength, muscle endurance, power, jumping performance and exercise speed. However, not all analyses provided a definite direction for the effect of caffeine when considering the 95% prediction interval. Using the Grading of Recommendations Assessment, Development and Evaluation criteria the quality of evidence was generally categorised as moderate (with some low to very low quality of evidence). Most individual studies included in the published meta-analyses were conducted among young men.Summary/conclusionSynthesis of the currently available meta-analyses suggest that caffeine ingestion improves exercise performance in a broad range of exercise tasks. Ergogenic effects of caffeine on muscle endurance, muscle strength, anaerobic power and aerobic endurance were substantiated by moderate quality of evidence coming from moderate-to-high quality systematic reviews. For other outcomes, we found moderate quality reviews that presented evidence of very low or low quality. It seems that the magnitude of the effect of caffeine is generally greater for aerobic as compared with anaerobic exercise. More primary studies should be conducted among women, middle-aged and older adults to improve the generalisability of these findings.


BMJ Open ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. e046476
Author(s):  
Emma Axon ◽  
Joanne R Chalmers ◽  
Miriam Santer ◽  
Matthew J Ridd ◽  
Sandra Lawton ◽  
...  

ObjectiveAn umbrella review summarising all safety data from systematic reviews of topical corticosteroids (TCS) in adults and children with atopic eczema.MethodsEmbase, MEDLINE, PubMed, Cochrane Database of Systematic Reviews and the Centre of Evidence Based Dermatology map of eczema systematic reviews were searched until 7 November 2018 and Epistemonikos until 2 March 2021. Reviews were included if they assessed the safety of TCS in atopic eczema and searched >1 database using a reproducible search strategy. Review quality was assessed using version 2 of 'A MeaSurement Tool to Assess systematic Reviews' (AMSTAR 2 tool).Results38 systematic reviews included, 34 low/critically low quality. Treatment and follow-up were usually short (2–4 weeks).Key findingsTCS versus emollient/vehicle: No meta-analyses identified for skin-thinning. Two 2-week randomised controlled trials (RCTs) found no significant increased risk with very potent TCS (0/196 TCS vs 0/33 vehicle in children and 6/109 TCS vs 2/50 vehicle, age unknown). Biochemical adrenal suppression (cortisol) was 3.8% (95% CI 2.4% to 5.8%) in a meta-analysis of 11 uncontrolled observational studies (any potency TCS, 522 children). Effects reversed when treatment ceased.TCS versus topical calcineurin inhibitors: Meta-analysis showed higher relative risk of skin thinning with TCS (4.86, 95% CI 1.06 to 22.28, n=4128, four RCTs, including one 5-year RCT). Eight cases in 2068 participants, 7 using potent TCS. No evidence of growth suppression.Once daily versus more frequent TCS: No meta-analyses identified. No skin-thinning in one RCT (3 weeks potent TCS, n=94) or biochemical adrenal suppression in two RCTs (up to 2 weeks very potent/moderate TCS, n=129).TCS twice/week to prevent flares (‘weekend therapy’) versus vehicle: No meta-analyses identified. No evidence of skin thinning in five RCTs. One RCT found biochemical adrenal suppression (2/44 children, potent TCS).ConclusionsWe found no evidence of harm when TCS were used intermittently ‘as required’ to treat flares or ‘weekend therapy’ to prevent flares. However, long-term safety data were limited.PROSPERO registration numberCRD42018079409.


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