scholarly journals Evidence-Based Medicine, Systematic Reviews, and Guidelines in Interventional Pain Management: Part 6. Systematic Reviews and Meta-Analyses of Observational Studies

2008 ◽  
Vol 5;12 (5;9) ◽  
pp. 819-850
Author(s):  
Laxmaiah Manchikanti

Observational studies provide an important source of information when randomized controlled trials (RCTs) cannot or should not be undertaken, provided that the data are analyzed and interpreted with special attention to bias. Evidence-based medicine (EBM) stresses the examination of evidence from clinical research and describes it as a shift in medical paradigm, in contrast to intuition, unsystematic clinical experience, and pathophysiologic rationale. While the importance of randomized trials has been created by the concept of the hierarchy of evidence in guiding therapy, much of the medical research is observational. The reporting of observational research is often not detailed and clear enough with insufficient quality and poor reporting, which hampers the assessment of strengths and weaknesses of the study and the generalizability of the mixed results. Thus, in recent years, progress and innovations in health care are measured by systematic reviews and meta-analyses. A systematic review is defined as, “the application of scientific strategies that limit bias by the systematic assembly, clinical appraisal, and synthesis of all relevant studies on a specific topic.” Meta-analysis usually is the final step in a systematic review. Systematic reviews and meta-analyses are labor intensive, requiring expertise in both the subject matter and review methodology, and also must follow the rules of EBM which suggests that a formal set of rules must complement medical training and common sense for clinicians to integrate the results of clinical research effectively. While expertise in the review methods is important, the expertise in the subject matter and technical components is also crucial. Even though, systematic reviews and meta-analyses, specifically of RCTs, have exploded, the quality of the systematic reviews is highly variable and consequently, the opinions reached of the same studies are quite divergent. Numerous deficiencies have been described in methodologic assessment of the quality of the individual articles. Consequently, observational studies can provide an important complementary source of information, provided that the data are analyzed and interpreted in the context of confounding bias to which they are prone. Appropriate systematic reviews of observational studies, in conjunction with RCTs, may provide the basis for elimination of a dangerous discrepancy between the experts and the evidence. Steps in conducting systematic reviews of observational studies include planning, conducting, reporting, and disseminating the results. MOOSE, or Meta-analysis of Observational Studies in Epidemiology, a proposal for reporting contains specifications including background, search strategy, methods, results, discussion, and conclusion. Use of the MOOSE checklist should improve the usefulness of meta-analysis for authors, reviewers, editors, readers, and decision-makers. This manuscript describes systematic reviews and meta-analyses of observational studies. Authors frequently utilize RCTs and observational studies in one systematic review; thus, they should also follow the reporting standards of the Quality of Reporting of Meta-analysis (QUOROM) statement, which also provides a checklist. A combined approach of QUOROM and MOOSE will improve reporting of systematic reviews and lead to progress and innovations in health care. Key words: Observational studies, evidence-based medicine, systematic reviews, metaanalysis, randomized trials, case-control studies, cross-sectional studies, cohort studies, confounding bias, QUOROM, MOOSE

Neurosurgery ◽  
2020 ◽  
Vol 87 (3) ◽  
pp. 435-441 ◽  
Author(s):  
Victor M Lu ◽  
Christopher S Graffeo ◽  
Avital Perry ◽  
Michael J Link ◽  
Fredric B Meyer ◽  
...  

Abstract Systematic reviews and meta-analyses in the neurosurgical literature have surged in popularity over the last decade. It is our concern that, without a renewed effort to critically interpret and appraise these studies as high or low quality, we run the risk of the quality and value of evidence-based medicine in neurosurgery being misinterpreted. Correspondingly, we have outlined 4 major domains to target in interpreting neurosurgical systematic reviews and meta-analyses based on the lessons learned by a collaboration of clinicians and academics summarized as 4 pearls. The domains of (1) heterogeneity, (2) modeling, (3) certainty, and (4) bias in neurosurgical systematic reviews and meta-analyses were identified as aspects in which the authors’ approaches have changed over time to improve robustness and transparency. Examples of how and why these pearls were adapted were provided in areas of cranial neuralgia, spine, pediatric, and neuro-oncology to demonstrate how neurosurgical readers and writers may improve their interpretation of these domains. The incorporation of these pearls into practice will empower neurosurgical academics to effectively interpret systematic reviews and meta-analyses, enhancing the quality of our evidence-based medicine literature while maintaining a critical focus on the needs of the individual patients in neurosurgery.


2021 ◽  
Vol 1 (2) ◽  
pp. 122-126
Author(s):  
Pallavi Patro ◽  
Durga Prasanna Misra

Systematic reviews are considered as the highest rung in the ladder of evidence-based medicine. They are bound by a pre-defined structure and requirement for extensive literature searches, when compared with the more liberal format of narrative reviews. Systematic review protocols should ideally be pre-registered to avoid duplication or redundancy. After defining clear review question(s), thorough literature searches form the basis of systematic reviews. Presentation of results should be qualitative or quantitative (meta-analysis) if the data is homogenous enough to permit pooling across multiple studies. Quality of individual studies by Cochrane risk of bias 2 tool for interventional studies and other suitable scales for observational studies, as well as appropriate assessment of publication bias are recommended. Certainty of outcomes should be assessed by the GRADE profiler. Finally, systematic reviews should conclude with recommendations for future research, based on their findings.


Author(s):  
Morteza Arab-Zozani ◽  
Zahra Heidarifard ◽  
Efat Jabarpour

Context: The number of studies on health is increasing rapidly worldwide and in Iran. Systematic review studies, meta-analyses, and economic evaluation are of great importance in evidence-based decision making because of their standing in the evidence-based pyramid. The purpose of this study was to evaluate the reporting and methodological quality of Iranian systematic reviews, meta-analysis studies and economic evaluations on healthcare. Evidence Acquisition: PubMed and Scopus databases were searched to find considered studies, including systematic reviews, meta analyses and economic evaluations published from 2005 to 2015. Because of the high volume of review studies, 10% of all systematic reviews and meta-analyses were selected as a random sample. Also, all economic evaluations were included. Articles were evaluated using checklists, including PRISMA, AMSTAR and QHES with a maximum score of 27, 11 and 100, respectively. The quality score for each criterion as well as the epidemiological and descriptive characteristics of all articles was determined. Data were analyzed using SPSS V. 16 software. Results: After searching the databases, 1084 systematic reviews and meta-analyses were obtained, 10% of which were included in the study. A total of 41 economic evaluations were also included. The mean scores of systematic reviews and meta-analyses based on PRISMA and AMSTAR checklists were 17.04 (5.35) and 5.42 (1.97), respectively, and 68.21 (12.44) for economic evaluations based on QHES. Only three systematic reviews and meta-analysis articles had recorded protocols and 85% of the studies included the terms “systematic review” and “meta-analysis” in their titles. Only one study had been updated. In addition, 81% of the systematic reviews and meta-analyses were published in specialized journals and 47% in Iranian journals. Financial resources and conflict of interests had been mentioned in 33% and 66% of the studies, respectively. Of the selected studies, 60% had evaluated the quality of the articles and 35% of the studies had assessed publication bias. In economic evaluations, 56% had used CEA analysis, 22% CUA analysis, 12% CBA analysis, and one study had used CMA analysis. Of these studies, 54% were model-based health economic studies and 12% were trial-based. The economic perspective was the health care system in most studies. Forty-four percent of the studies had a short time horizon of one year or less, whereas 33% had a lifetime horizon. Moreover, 68% of the studies showed sensitivity analysis and only 5 included the magnitude and direction of the bias. Conclusions: Overall, the reporting and methodological quality of the selected studies were estimated at a moderate level. Based on these results, it is recommended to adopt strategies to reduce preventable errors in studies. Having a primary plan and protocol and registering it as a systematic review can be an important factor in improving the quality of studies. Economic evaluations should also focus on issues, such as economic perspective, time horizon, available bias, and sensitivity analysis.


2009 ◽  
Vol 1;12 (1;1) ◽  
pp. 35-42
Author(s):  
Laxmaiah Manchikanti

In recent years, progress and innovations in healthcare are measured by evidencebased medicine (EBM), systematic reviews, and meta-analyses. A systematic review is defined as, “the application of scientific strategies that limit bias by the systematic assembly, critical appraisal, and synthesis of all relevant studies on a specific topic.” In contrast, meta-analysis is the statistical pooling of data across studies to generate pooled estimates of effects. Meta-analysis usually is the final step in a systematic review. Systematic reviews and meta-analyses are labor intensive, requiring expertise in both the subject matter and review methodology, and also must follow the rules of EBM which suggest that a formal set of rules must complement medical training and common sense for clinicians to interpret the results of clinical research effectively. While expertise in the subject matter is crucial, expertise in review methods is also particularly important. Despite an explosion of systematic reviews and meta-analyses, the empiric research on the quality of systematic reviews has shown that not all systematic reviews are truly systematic, having highly variable quality, deficiencies in methodologic assessment of the quality of the included manuscripts, and bias. Even then, systematic review of the literature is currently the best, least biased, and most rational way to organize, cull, evaluate, and integrate the research evidence from among the expanding medical and healthcare literature. However, a dangerous discrepancy between the experts and the evidence continues to persist in part because multiple instruments are available to assess the quality of systematic reviews or meta-analyses. Steps in conducting systematic reviews include planning, conducting, reporting, and disseminating the results. The Quality of Reporting of Meta-analysis (QUOROM) statement provides a checklist and a flow diagram. The checklist describes the preferred way to present the abstract, introduction, methods, results, and discussion sections of the report of an analysis. This review describes various aspects of systematic reviews and meta-analyses of randomized trials with a special focus on interventional pain management. Key words: Randomized trials, pragmatic trials, evidence-based medicine, systematic reviews, meta-analyses, guidelines, bias, interventional pain management, Quality of Reporting of Meta-analysis (QUOROM), Cochrane reviews


Cephalalgia ◽  
2006 ◽  
Vol 26 (11) ◽  
pp. 1265-1274 ◽  
Author(s):  
P Tfelt-Hansen

The following systematic reviews and meta-analyses are presented and the results discussed: the evidence-based American guidelines, five systematic reviews on naratriptan, rizatriptan, eletriptan, sumatriptan and propranolol; a meta-analysis of sumatriptan, a meta-analysis of acute migraine therapy, a meta-analysis of triptans available in Canada and a large meta-analysis of oral triptans. The systematic reviews of several randomized trials of one drug overcome random effects in estimating treatment effect of the reviewed drug. The results from the large meta-analysis of several drugs are compared with head-to-head comparative trials. Results are generally the same in the meta-analysis and in the comparative trials, with some exceptions. Head-to-head comparisons should remain the ‘gold standard’ and meta-analyses are a useful supplement in cases when comparative trials are relatively small and when no comparative trials exist.


Author(s):  
Paul Harrison ◽  
Philip Cowen ◽  
Tom Burns ◽  
Mina Fazel

‘Evidence-based approaches to psychiatry’ describes the application of evidence-based medicine (EBM) to psychiatric practice. The chapter covers the key processes in EBM, including the formulation of a clinically relevant question, the systematic search for high-quality evidence and the meta-analytic synthesis of data. It demonstrates how evidence-based approaches to psychiatry have led to important developments showing quantitative effects of different treatments through advanced meta-analysis of data from randomized trials. This has underpinned the development of clinical guidelines that have the aim of improving the reliability and quality of treatments that patients receive. The chapter also describes how meta-analyses should be critically reviewed, as well as their problems and limitations. Not all relevant questions in psychiatric research are susceptible to the quantitative approach offered by EBM, and the chapter also outlines how qualitative methodologies can play a key role in answering important questions related, for example, to the patient experience.


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.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Line Kessel ◽  
Jens Andresen ◽  
Ditte Erngaard ◽  
Per Flesner ◽  
Britta Tendal ◽  
...  

The aim of the present systematic review was to examine the benefits and harms associated with immediate sequential bilateral cataract surgery (ISBCS) with specific emphasis on the rate of complications, postoperative anisometropia, and subjective visual function in order to formulate evidence-based national Danish guidelines for cataract surgery. A systematic literature review in PubMed, Embase, and Cochrane central databases identified three randomized controlled trials that compared outcome in patients randomized to ISBCS or bilateral cataract surgery on two different dates. Meta-analyses were performed using the Cochrane Review Manager software. The quality of the evidence was assessed using the GRADE method (Grading of Recommendation, Assessment, Development, and Evaluation). We did not find any difference in the risk of complications or visual outcome in patients randomized to ISBCS or surgery on two different dates. The quality of evidence was rated as low to very low. None of the studies reported the prevalence of postoperative anisometropia. In conclusion, we cannot provide evidence-based recommendations on the use of ISBCS due to the lack of high quality evidence. Therefore, the decision to perform ISBCS should be taken after careful discussion between the surgeon and the patient.


2012 ◽  
Vol 21 (2) ◽  
pp. 151-153 ◽  
Author(s):  
A. Cipriani ◽  
C. Barbui ◽  
C. Rizzo ◽  
G. Salanti

Standard meta-analyses are an effective tool in evidence-based medicine, but one of their main drawbacks is that they can compare only two alternative treatments at a time. Moreover, if no trials exist which directly compare two interventions, it is not possible to estimate their relative efficacy. Multiple treatments meta-analyses use a meta-analytical technique that allows the incorporation of evidence from both direct and indirect comparisons from a network of trials of different interventions to estimate summary treatment effects as comprehensively and precisely as possible.


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