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Gordon H. Guyatt

Bio: Gordon H. Guyatt is an academic researcher from McMaster University. The author has contributed to research in topics: Randomized controlled trial & Evidence-based medicine. The author has an hindex of 231, co-authored 1620 publications receiving 228631 citations. Previous affiliations of Gordon H. Guyatt include Memorial Sloan Kettering Cancer Center & Cayetano Heredia University.


Papers
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Journal ArticleDOI
01 Jan 2013-BMJ Open
TL;DR: More than 20 years after its introduction, the EBP paradigm has been embraced by healthcare professionals as an important means to improve quality of patient care, but its implementation is still deficient.
Abstract: Objectives Evidence-based practice (EBP) may help improve healthcare quality. However, not all healthcare professionals and managers use EBP in their daily practice. We systematically reviewed the literature to summarise self-reported appreciation of EBP and organisational infrastructure solutions proposed to promote EBP. Design Systematic review. Two investigators independently performed the systematic reviewing process. Information sources MEDLINE, EMBASE and Cochrane Library were searched for publications between 2000 and 2011. Eligibility criteria for included studies Reviews and surveys of EBP attitude, knowledge, awareness, skills, barriers and facilitators among managers, doctors and nurses in clinical settings. Results We found 31 surveys of fairly good quality. General attitude towards EBP was welcoming. Respondents perceived several barriers, but also many facilitators for EBP implementation. Solutions were proposed at various organisational levels, including (inter)national associations and hospital management promoting EBP, pregraduate and postgraduate education, as well as individual support by EBP mentors on the wards to move EBP from the classroom to the bedside. Conclusions More than 20 years after its introduction, the EBP paradigm has been embraced by healthcare professionals as an important means to improve quality of patient care, but its implementation is still deficient. Policy exerted at microlevel , middlelevel and macrolevel, and supported by professional, educational and managerial role models, may further facilitate EBP.

147 citations

Journal ArticleDOI
TL;DR: Guideline panels should not GRADE good practice statements, according to a review of evidence-based medicine and health outcomes research.

146 citations

Journal ArticleDOI
TL;DR: The development of explicit, hypothesis-driven, and iterative approaches to outcome measure development, patterned on approaches used in the fields of rheumatology and oncology, may improve the conduct of clinical studies in the critically ill.
Abstract: Background and Objectives: Sepsis is the leading cause of morbidity and mortality for patients admitted to an intensive care unit. The evaluation of new therapies has been hampered by the underdevelopment of outcome measures used to detect biological activity and patient-centered benefit in a complex and highly heterogeneous patient population. We sought to evaluate existing approaches and to draw on insights from other disciplines to propose a comprehensive approach to outcome evaluation in sepsis clinical trials. Methods: An expert colloquium organized by the International Sepsis Forum brought together sepsis researchers, clinical epidemiologists, and experts in the development and implementation of outcome measures in rheumatology, neurology, and oncology. Results: The translation of an evolving understanding of the biology of sepsis into effective new therapies for critically ill patients requires a reevaluation of the end points used to determine response to intervention. These represent a continuum that measures biological activity against the target at one end and sustained improvement in survival or quality of life at the other. Early phase research should determine whether an intervention works in vivo, using measures that are responsive and informative to provide proof of principle, to aid in selecting optimal patient populations for study, and to gain insights into optimal dose and duration of therapy. After in vivo biology has been demonstrated and the possibility of efficacy inferred by plausible improvements in surrogate physiologic measures, definitive studies should seek robust evidence of benefit using end points that measure important, patient-centered benefit, including intermediate and longer term survival and health-related quality of life. Nonmortal measures of benefit assume particular importance for populations, such as children, whose mortality risk is low, or who have significant rates of comorbidities that independently limit survival. Composite measures that integrate morbidity and mortality effects may provide the most meaningful information about therapeutic efficacy. Conclusions: The development of explicit, hypothesis-driven, and iterative approaches to outcome measure development, patterned on approaches used in the fields of rheumatology and oncology, may improve the conduct of clinical studies in the critically ill. LEARNING OBJECTIVES On completion of this article, the reader should be able to: LEARNING OBJECTIVES Dr. Marshall has disclosed that he was formerly a consultant for Edwards and Wyeth-Ayerst and is currently a consultant for BRAHMS Diagnostics, and GlaxoSmithKline. Dr. Bernard has disclosed that he has been the recipient of grant/research funds from Eli Lilly, Novo Nordisk, and Takeda Pharmaceuticals. Dr. Bonbardier has disclosed that she has been the recipient of grant/research funds from Abbott and Amgen, is a consultant/advisor for and is on the speakers bureau of Merck, Pfizer, Schering-Plough Corp., and Wyeth. Dr. Calandra has disclosed that he is the recipient of direct grant/research funding from Baxter, Wako, and Merck and was the recipient of direct grant/research funding from Pfizer, Natimmune, Bristol-Myers Squibb in the past; a consultant/advisor for Baxter, Pfizer, Merck, GlaxoSmithKline, CAT, Roche; and on the speakers bureau of Pfizer and Merck and was formerly on the speakers bureau of GlaxoSmithKline. The remaining authors have disclosed that they have no financial relationships or interest in any commercial companies pertaining to this educational activity. LEARNING OBJECTIVES Wolters Kluwer Health has identified and resolved all faculty conflicts of interests regarding this educational activity. LEARNING OBJECTIVES Visit the Critical Care Medicine Web site (www.ccmjournal.org) for information on obtaining continuing medical education credit.

145 citations

Journal ArticleDOI
01 Jun 2008-Chest
TL;DR: This chapter about antithrombotic therapy for coronary artery disease is part of the AntithromBotic and Thrombolytic Therapy: American College of Chest Physicans Evidence-Based Clinical Practice Guidelines (8th Edition).

144 citations

Journal ArticleDOI
TL;DR: The primary aim of this paper is to present a cogent and concise description for clinicians to facilitate the incorporation of QOL assessments into oncology clinical research and practice.
Abstract: Background A series of six manuscripts with an introduction appeared in the Mayo Clinic Proceedings, based upon the collective effort of 30 individuals with an interest and expertise in assessing the clinical significance of quality of life (QOL) assessments. The series of manuscripts described the state of the science of QOL assessments in oncology clinical research and practice and included extensive literature and theoretical justification for the continued inclusion of QOL in oncology clinical research and practice.

143 citations


Cited by
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Journal ArticleDOI
TL;DR: Moher et al. as mentioned in this paper introduce PRISMA, an update of the QUOROM guidelines for reporting systematic reviews and meta-analyses, which is used in this paper.
Abstract: David Moher and colleagues introduce PRISMA, an update of the QUOROM guidelines for reporting systematic reviews and meta-analyses

62,157 citations

Journal Article
TL;DR: The QUOROM Statement (QUality Of Reporting Of Meta-analyses) as mentioned in this paper was developed to address the suboptimal reporting of systematic reviews and meta-analysis of randomized controlled trials.
Abstract: Systematic reviews and meta-analyses have become increasingly important in health care. Clinicians read them to keep up to date with their field,1,2 and they are often used as a starting point for developing clinical practice guidelines. Granting agencies may require a systematic review to ensure there is justification for further research,3 and some health care journals are moving in this direction.4 As with all research, the value of a systematic review depends on what was done, what was found, and the clarity of reporting. As with other publications, the reporting quality of systematic reviews varies, limiting readers' ability to assess the strengths and weaknesses of those reviews. Several early studies evaluated the quality of review reports. In 1987, Mulrow examined 50 review articles published in 4 leading medical journals in 1985 and 1986 and found that none met all 8 explicit scientific criteria, such as a quality assessment of included studies.5 In 1987, Sacks and colleagues6 evaluated the adequacy of reporting of 83 meta-analyses on 23 characteristics in 6 domains. Reporting was generally poor; between 1 and 14 characteristics were adequately reported (mean = 7.7; standard deviation = 2.7). A 1996 update of this study found little improvement.7 In 1996, to address the suboptimal reporting of meta-analyses, an international group developed a guidance called the QUOROM Statement (QUality Of Reporting Of Meta-analyses), which focused on the reporting of meta-analyses of randomized controlled trials.8 In this article, we summarize a revision of these guidelines, renamed PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses), which have been updated to address several conceptual and practical advances in the science of systematic reviews (Box 1). Box 1 Conceptual issues in the evolution from QUOROM to PRISMA

46,935 citations

Journal ArticleDOI
04 Sep 2003-BMJ
TL;DR: A new quantity is developed, I 2, which the authors believe gives a better measure of the consistency between trials in a meta-analysis, which is susceptible to the number of trials included in the meta- analysis.
Abstract: Cochrane Reviews have recently started including the quantity I 2 to help readers assess the consistency of the results of studies in meta-analyses. What does this new quantity mean, and why is assessment of heterogeneity so important to clinical practice? Systematic reviews and meta-analyses can provide convincing and reliable evidence relevant to many aspects of medicine and health care.1 Their value is especially clear when the results of the studies they include show clinically important effects of similar magnitude. However, the conclusions are less clear when the included studies have differing results. In an attempt to establish whether studies are consistent, reports of meta-analyses commonly present a statistical test of heterogeneity. The test seeks to determine whether there are genuine differences underlying the results of the studies (heterogeneity), or whether the variation in findings is compatible with chance alone (homogeneity). However, the test is susceptible to the number of trials included in the meta-analysis. We have developed a new quantity, I 2, which we believe gives a better measure of the consistency between trials in a meta-analysis. Assessment of the consistency of effects across studies is an essential part of meta-analysis. Unless we know how consistent the results of studies are, we cannot determine the generalisability of the findings of the meta-analysis. Indeed, several hierarchical systems for grading evidence state that the results of studies must be consistent or homogeneous to obtain the highest grading.2–4 Tests for heterogeneity are commonly used to decide on methods for combining studies and for concluding consistency or inconsistency of findings.5 6 But what does the test achieve in practice, and how should the resulting P values be interpreted? A test for heterogeneity examines the null hypothesis that all studies are evaluating the same effect. The usual test statistic …

45,105 citations

Journal ArticleDOI
13 Sep 1997-BMJ
TL;DR: Funnel plots, plots of the trials' effect estimates against sample size, are skewed and asymmetrical in the presence of publication bias and other biases Funnel plot asymmetry, measured by regression analysis, predicts discordance of results when meta-analyses are compared with single large trials.
Abstract: Objective: Funnel plots (plots of effect estimates against sample size) may be useful to detect bias in meta-analyses that were later contradicted by large trials. We examined whether a simple test of asymmetry of funnel plots predicts discordance of results when meta-analyses are compared to large trials, and we assessed the prevalence of bias in published meta-analyses. Design: Medline search to identify pairs consisting of a meta-analysis and a single large trial (concordance of results was assumed if effects were in the same direction and the meta-analytic estimate was within 30% of the trial); analysis of funnel plots from 37 meta-analyses identified from a hand search of four leading general medicine journals 1993-6 and 38 meta-analyses from the second 1996 issue of the Cochrane Database of Systematic Reviews . Main outcome measure: Degree of funnel plot asymmetry as measured by the intercept from regression of standard normal deviates against precision. Results: In the eight pairs of meta-analysis and large trial that were identified (five from cardiovascular medicine, one from diabetic medicine, one from geriatric medicine, one from perinatal medicine) there were four concordant and four discordant pairs. In all cases discordance was due to meta-analyses showing larger effects. Funnel plot asymmetry was present in three out of four discordant pairs but in none of concordant pairs. In 14 (38%) journal meta-analyses and 5 (13%) Cochrane reviews, funnel plot asymmetry indicated that there was bias. Conclusions: A simple analysis of funnel plots provides a useful test for the likely presence of bias in meta-analyses, but as the capacity to detect bias will be limited when meta-analyses are based on a limited number of small trials the results from such analyses should be treated with considerable caution. Key messages Systematic reviews of randomised trials are the best strategy for appraising evidence; however, the findings of some meta-analyses were later contradicted by large trials Funnel plots, plots of the trials9 effect estimates against sample size, are skewed and asymmetrical in the presence of publication bias and other biases Funnel plot asymmetry, measured by regression analysis, predicts discordance of results when meta-analyses are compared with single large trials Funnel plot asymmetry was found in 38% of meta-analyses published in leading general medicine journals and in 13% of reviews from the Cochrane Database of Systematic Reviews Critical examination of systematic reviews for publication and related biases should be considered a routine procedure

37,989 citations

Journal ArticleDOI
TL;DR: The GLOBOCAN 2020 estimates of cancer incidence and mortality produced by the International Agency for Research on Cancer (IARC) as mentioned in this paper show that female breast cancer has surpassed lung cancer as the most commonly diagnosed cancer, with an estimated 2.3 million new cases (11.7%), followed by lung cancer, colorectal (11 4.4%), liver (8.3%), stomach (7.7%) and female breast (6.9%), and cervical cancer (5.6%) cancers.
Abstract: This article provides an update on the global cancer burden using the GLOBOCAN 2020 estimates of cancer incidence and mortality produced by the International Agency for Research on Cancer. Worldwide, an estimated 19.3 million new cancer cases (18.1 million excluding nonmelanoma skin cancer) and almost 10.0 million cancer deaths (9.9 million excluding nonmelanoma skin cancer) occurred in 2020. Female breast cancer has surpassed lung cancer as the most commonly diagnosed cancer, with an estimated 2.3 million new cases (11.7%), followed by lung (11.4%), colorectal (10.0 %), prostate (7.3%), and stomach (5.6%) cancers. Lung cancer remained the leading cause of cancer death, with an estimated 1.8 million deaths (18%), followed by colorectal (9.4%), liver (8.3%), stomach (7.7%), and female breast (6.9%) cancers. Overall incidence was from 2-fold to 3-fold higher in transitioned versus transitioning countries for both sexes, whereas mortality varied <2-fold for men and little for women. Death rates for female breast and cervical cancers, however, were considerably higher in transitioning versus transitioned countries (15.0 vs 12.8 per 100,000 and 12.4 vs 5.2 per 100,000, respectively). The global cancer burden is expected to be 28.4 million cases in 2040, a 47% rise from 2020, with a larger increase in transitioning (64% to 95%) versus transitioned (32% to 56%) countries due to demographic changes, although this may be further exacerbated by increasing risk factors associated with globalization and a growing economy. Efforts to build a sustainable infrastructure for the dissemination of cancer prevention measures and provision of cancer care in transitioning countries is critical for global cancer control.

35,190 citations