Browsing by Author "Guyatt, Gordon H."

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    A guide for health professionals to interpret and use recommendations in guidelines developed with the GRADE approach
    (2016) Neumann, Ignacio; Santesso, Nancy; Akl, Elie A.; Rind, David M.; Vandvik, Per Olav; Alonso-Coello, Pablo; Agoritsas, Thomas; Mustafa, Reem A.; Alexander, Paul Elias; Schuenemann, Holger; Guyatt, Gordon H.
    An increasing number of organizations worldwide are using new and improved standards for developing trustworthy clinical guidelines. One of such approaches, developed by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) working group, offers systematic and transparent guidance in moving from evidence to recommendations. The GRADE strategy concentrates on four factors: the balance between benefits and harms, the certainty of the evidence, values and preferences, and resource considerations. However, it also considers issues around feasibility, equity, and acceptability of recommendations. GRADE distinguishes two types of recommendations: strong and weak. Strong recommendations reflect a clear preference for one alternative and should apply to all or almost all patients, obviating the need for a careful review of the evidence with each patient. Weak recommendations are appropriate when there is a close balance between desirable and undesirable consequences of alternative management strategies, uncertainty regarding the effects of the alternatives, uncertainty or variability in patients' values and preferences, or questionable cost-effectiveness. Weak recommendations usually require accessing the underlying evidence and a shared decision-making approach. Clinicians using GRADE recommendations should understand the meaning of the strength of the recommendation, be able to critically appraise the recommendation, and apply trustworthy recommendations according to their strength. (C) 2016 Elsevier Inc. All rights reserved.
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    A practical approach to evidence-based dentistry : VII How to use patient management recommendations from clinical practice guidelines
    (2015) Carrasco Labra, Alonso; Brignardello Petersen, Romina; Glick, Michael; Guyatt, Gordon H.; Neumann Burotto, Gonzalo Ignacio; Azarpazhooh, Amir
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    Compelling evidence from meta-epidemiological studies demonstrates overestimation of effects in randomized trials that fail to optimize randomization and blind patients and outcome assessors
    (2024) Wang, Ying; Parpia, Sameer; Couban, Rachel; Wang, Qi; Armijo-Olivo, Susan; Bassler, Dirk; Briel, Matthias; Brignardello-Petersen, Romina; Gluud, Lise Lotte; Keitz, Sheri A.; Letelier, Luz M.; Ravaud, Philippe; Schulz, Kenneth F.; Siemieniuk, Reed A. C.; Zeraatkar, Dena; Guyatt, Gordon H.
    Objectives: To investigate the impact of potential risk of bias elements on effect estimates in randomized trials. Study Design and Setting: We conducted a systematic survey of meta-epidemiological studies examining the influence of potential risk of bias elements on effect estimates in randomized trials. We included only meta-epidemiological studies that either preserved the clustering of trials within meta-analyses (compared effect estimates between trials with and without the potential risk of bias element within each meta-analysis, then combined across meta-analyses; between-trial comparisons), or preserved the clustering of substudies within trials (compared effect estimates between substudies with and without the element, then combined across trials; within-trial comparisons). Sepa-rately for studies based on between-and within-trial comparisons, we extracted ratios of odds ratios (RORs) from each study and combined them using a random-effects model. We made overall inferences and assessed certainty of evidence based on Grading of Recommendations, Assessment, development, and Evaluation and Instrument to assess the Credibility of Effect Modification Analyses. Results: Forty-one meta-epidemiological studies (34 of between-, 7 of within-trial comparisons) proved eligible. Inadequate random sequence generation (ROR 0.94, 95% confidence interval [CI] 0.90-0.97) and allocation concealment (ROR 0.92, 95% CI 0.88-0.97) probably lead to effect overestimation (moderate certainty). Lack of patients blinding probably overestimates effects for patient -reported outcomes (ROR 0.36, 95% CI 0.28-0.48; moderate certainty). Lack of blinding of outcome assessors results in effect overesti-mation for subjective outcomes (ROR 0.69, 95% CI 0.51-0.93; high certainty). The impact of patients or outcome assessors blinding on other outcomes, and the impact of blinding of health-care providers, data collectors, or data analysts, remain uncertain. Trials stopped early for benefit probably overestimate effects (moderate certainty). Trials with imbalanced cointerventions may overestimate effects, while trials with missing outcome data may underestimate effects (low certainty). Influence of baseline imbalance, compliance, selective reporting, and intention-to-treat analysis remain uncertain. Conclusion: Failure to ensure random sequence generation or adequate allocation concealment probably results in modest overestimates of effects. Lack of patients blinding probably leads to substantial overestimates of effects for patient-reported outcomes. Lack of blinding of outcome assessors results in substantial effect overestimation for subjective outcomes. For other elements, though evidence for consistent systematic overestimate of effect remains limited, failure to implement these safeguards may still introduce important bias. (c) 2023 Elsevier Inc. All rights reserved.
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    Completion and publication rates of randomized controlled trials in surgery an empirical study
    (2015) Rosenthal, Rachel; Kasenda, Benjamin; Dell-Kuster, Salome; Von Elm, Erik; You, John; Neumann Burotto, Gonzalo Ignacio; Tomonaga, Yuki; Saccilotto, Ramon; Amstutz, Alain; Bengough, Theresa; Meerpohl, Joerg J.; Stegert, Mihaela; Tikkinen, Kari A. O.; Blümle, Anette; Carrasco-Labra, Alonso; Faulhaber, Markus; Mulla, Sohail; Mertz, Dominik; Akl, Elie A.; Bassler, Dirk; Busse, Jason W.; Ferreira-González, Ignacio; Lamontagne, Francois; Nordmann, Alain; Gloy, Viktoria; Olu, Kelechi K.; Raatz, Heike; Moja, Lorenzo; Ebrahim, Shanil; Schandelmaier, Stefan; Sun, Xin; Vandvik, Per O.; Johnston, Bradley C.; Walter, Martin A.; Burnand, Bernard; Schwenkglenks, Matthias; Hemkens, Lars G.; Bucher, Heiner C.; Guyatt, Gordon H.; Briel, Matthias
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    Evaluating patient values and preferences for thromboprophylaxis decision making during pregnancy: a study protocol
    (2012) Alonso Coello, Pablo.; Neumann Burotto, Gonzalo Ignacio; Ebrahim, Shanil; Guyatt, Gordon H.; Tikkinen, Kari A.; Eckman, Mark H.; McDonald, Sarah D.; Akl, Elie A.; Bates, Shannon M.
    Abstract Background Pregnant women with prior venous thromboembolism (VTE) are at risk of recurrence. Low molecular weight heparin (LWMH) reduces the risk of pregnancy-related VTE. LMWH prophylaxis is, however, inconvenient, uncomfortable, costly, medicalizes pregnancy, and may be associated with increased risks of obstetrical bleeding. Further, there is uncertainty in the estimates of both the baseline risk of pregnancy-related recurrent VTE and the effects of antepartum LMWH prophylaxis. The values and treatment preferences of pregnant women, crucial when making recommendations for prophylaxis, are currently unknown. The objective of this study is to address this gap in knowledge. Methods We will perform a multi-center cross-sectional interview study in Canada, USA, Norway and Finland. The study population will consist of 100 women with a history of lower extremity deep vein thrombosis (DVT) or pulmonary embolism (PE), and who are either pregnant, planning pregnancy, or may in the future consider pregnancy (women between 18 and 45 years). We will exclude individuals who are on full dose anticoagulation or thromboprophylaxis, who have undergone surgical sterilization, or whose partners have undergone vasectomy. We will determine each participant's willingness to receive LMWH prophylaxis during pregnancy through direct choice exercises based on real life and hypothetical scenarios, preference-elicitation using a visual analog scale (“feeling thermometer”), and a probability trade-off exercise. The primary outcome will be the minimum reduction (threshold) in VTE risk at which women change from declining to accepting LMWH prophylaxis. We will explore possible determinants of this choice, including educational attainment, the characteristics of the women’s prior VTE, and prior experience with LMWH. We will determine the utilities that women place on the burden of LMWH prophylaxis, pregnancy-related DVT, pregnancy-related PE and pregnancy-related hemorrhage. We will generate a “personalized decision analysis” using participants’ utilities and their personalized risk of recurrent VTE as inputs to a decision analytic model. We will compare the personalized decision analysis to the participant’s stated choice. Discussion The preferences of pregnant women at risk of VTE with respect to the use of antithrombotic therapy remain unexplored. This research will provide explicit, quantitative expressions of women's valuations of health states related to recurrent VTE and its prevention with LMWH. This information will be crucial for both guideline developers and for clinicians.
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    Experiences with a novel policy for managing conflicts of interest of guideline developers : a descriptive qualitative study
    (2013) Neumann Burotto, Gonzalo Ignacio; Karl, Renee; Rajpal, Aman; Akl, Elie; Guyatt, Gordon H.
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    GRADE Evidence to Decision (EtD) frameworks: a systematic and transparent approach to making well informed healthcare choices. 1: Introduction
    (2016) Alonso-Coello, Pablo; Schunemann, Holger J.; Moberg, Jenny; Brignardello-Petersen, Romina; Akl, Elie A.; Davoli, Marina; Treweek, Shaun; Mustafa, Reem A.; Rada, Gabriel; Rosenbaum, Sarah; Morelli, Angela; Guyatt, Gordon H.; Oxman, Andrew D.
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    Instruments assessing risk of bias of randomized trials frequently included items that are not addressing risk of bias issues
    (2022) Wang, Ying; Ghadimi, Maryam; Wang, Qi; Hou, Liangying; Zeraatkar, Dena; Iqbal, Atiya; Ho, Cameron; Yao, Liang; Hu, Malini; Ye, Zhikang; Couban, Rachel; Armijo-Olivo, Susan; Bassler, Dirk; Briel, Matthias; Gluud, Lise Lotte; Glasziou, Paul; Jackson, Rod; Keitz, Sheri A.; Letelier, Luz M.; Ravaud, Philippe; Schulz, Kenneth F.; Siemieniuk, Reed A. C.; Brignardello-Petersen, Romina; Guyatt, Gordon H.
    Objectives: To establish whether items included in instruments published in the last decade assessing risk of bias of randomized controlled trials (RCTs) are indeed addressing risk of bias.Study Design and Setting: We searched Medline, Embase, Web of Science, and Scopus from 2010 to October 2021 for instruments assessing risk of bias of RCTs. By extracting items and summarizing their essential content, we generated an item list. Items that two re-viewers agreed clearly did not address risk of bias were excluded. We included the remaining items in a survey in which 13 experts judged the issue each item is addressing: risk of bias, applicability, random error, reporting quality, or none of the above.Results: Seventeen eligible instruments included 127 unique items. After excluding 61 items deemed as clearly not addressing risk of bias, the item classification survey included 66 items, of which the majority of respondents deemed 20 items (30.3%) as addressing risk of bias; the majority deemed 11 (16.7%) as not addressing risk of bias; and there proved substantial disagreement for 35 (53.0%) items. Conclusion: Existing risk of bias instruments frequently include items that do not address risk of bias. For many items, experts disagree on whether or not they are addressing risk of bias.(c) 2022 Elsevier Inc. All rights reserved.
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    Low Anonymous Voting Compliance With the Novel Policy for Managing Conflicts of Interest Implemented in the 9th Version of the American College of Chest Physicians Antithrombotic Guidelines
    (2013) Neumann, Ignacio; Akl, Elie A.; Valdes, Macarena; Bravo, Stephanie; Araos, Silvana; Kairouz, Victor; Schuenemann, Holger; Guyatt, Gordon H.
    Background: The executive committee of the Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (AT9) developed a strategy to limit the impact of conflict of interest (COI) on recommendations. This policy excluded conflicted panelists from voting on recommendations with which they had conflicts. The objective of the study is to explore the compliance of the attendees of the AT9 final conference.
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    Potential impact on estimated treatment effects of information lost to follow-up in randomised controlled trials (LOST-IT): systematic review
    (BMJ PUBLISHING GROUP, 2012) Akl, Elie A.; Briel, Matthias; You, John J.; Sun, Xin; Johnston, Bradley C.; Busse, Jason W.; Mulla, Sohail; Lamontagne, Francois; Bassler, Dirk; Vera, Claudio; Alshurafa, Mohamad; Katsios, Christina M.; Zhou, Qi; Cukierman Yaffe, Tali; Gangji, Azim; Mills, Edward J.; Walter, Stephen D.; Cook, Deborah J.; Schuenemann, Holger J.; Altman, Douglas G.; Guyatt, Gordon H.
    Objective To assess the reporting, extent, and handling of loss to follow-up and its potential impact on the estimates of the effect of treatment in randomised controlled trials.
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    Reporting handling and assessing the risk of bias associated with missing participant data in systematic reviews : a methodological survey
    (2015) Akl, Elie A.; Carrasco Labra, Alonso; Brignardello Petersen, Romina; Neumann Burotto, Gonzalo Ignacio; Johnston, Bradley C.; Sun, Xin; Briel, Matthias; Busse, Jason W; Ebrahim, Shanil; Granados, Carlos; Iorio, Alfonso; Irfan, Affan; Martínez García, Laura; Mustafa, Reem A.; Ramírez Morera, Anggie; Selva, Anna; Solà, Ivan; Sanabria, Andrea Juliana; Tikkinen, Kari A. O.; Vandvik, Per O.; Vernooij, Robin W. M.; Zazueta, Oscar E.; Zhou, Qi; Guyatt, Gordon H.; Alonso Coello, Pablo
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    Reporting missing participant data in randomised trials : systematic survey of the methodological literature and a proposed guide
    (2015) Akl, Elie A.; Shawwa, Khled; Kahale, Lara A.; Agoritsas, Thomas; Brignardello Petersen, Romina; Busse, Jason W.; Carrasco Labra, Alonso; Ebrahim, Shanil; Johnston, Bradley C.; Neumann Burotto, Gonzalo Ignacio; Sola, Ivan; Sun, Xin; Vandvik, Per; Zhang, Yuqing; Alonso Coello, Pablo; Guyatt, Gordon H.
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    Senior GRADE methodologists encounter challenges as part of WHO guideline development panels : an inductive content analysis
    (2016) Alexander, Paul E.; Li, Shelly-Anne; Gionfriddo, Michael R.; Stolzfus, Rebecca; Neumann Burotto, Gonzalo Ignacio; Brito, Juan P.; Djulbegovic, Benjamin; Montori, Víctor M.; Schünemann, Holger J.; Guyatt, Gordon H.
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    Specific instructions for estimating unclearly reported blinding status in randomized trials were reliable and valid
    (ELSEVIER SCIENCE INC, 2012) Akl, Elie A.; Sun, Xin; Busse, Jason W.; Johnston, Bradley C.; Briel, Matthias; Mulla, Sohail; You, John J.; Bassler, Dirk; Lamontagne, Francois; Vera, Claudio; Alshurafa, Mohamad; Katsios, Christina M.; Heels Ansdell, Diane; Zhou, Qi; Mills, Ed; Guyatt, Gordon H.
    Objective: To test the reliability and validity of specific instructions to classify blinding, when unclearly reported in randomized trials, as "probably done" or "probably not done."
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    Spotlight : Patient Centred Care Decision aids that really promote shared decision making : the pace quickens
    (2015) Agoritsas, Thomas; Heen, Anja Fog; Brandt, Linn; Alonso Coello, Pablo; Kristiansen, Annette; Akl, Elie A.; Neumann Burotto, Gonzalo Ignacio; Tikkinen, Kari; Van der Weijden, Trudy; Elwyn, Glyn; Montori, Victor M.; Guyatt, Gordon H.; Vandvik, Per Olav
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    Women's values and preferences and health state valuations for thromboprophylaxis during pregnancy : A cross-sectional interview study
    (2016) Bates, Shannon M.; Alonso Coello, Pablo; Tikkinen, Kari A. O.; Ebrahim, Shanil; Cruz Lopes, Luciane; McDonald, Sarah D.; Qi Zhou; Akl, Elie A.; Neumann Burotto, Gonzalo Ignacio; Jacobsen, Anne Flem; Yuqing Zhang; Santamaría, Amparo; Annichino Bizzacchi, Joyce Maria; Morten Sandset, Per; Bitar, Wael; Eckman, Mark H.; Guyatt, Gordon H.
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    Women’s Values and Preferences for Thromboprophylaxis during Pregnancy : A Comparison of Direct-choice and Decision Analysis using Patient Specific Utilities
    (2015) Eckman, Mark H.; Alonso-Coello, Pablo; Guyatt, Gordon H.; Ebrahim, Shanil; Tikkinen, Kari A.O.; Lopes, Luciane Cruz; Neumann Burotto, Gonzalo Ignacio; Mcdonald, Sarah D.; Zhang, Yuqing; Zhou, Qi; Akl, Elie A.; Jacobsen, Ann Flem; Santamaría, Amparo; Annichino-Bizzacchi, Joyce Maria; Bitar, Wael; Sandset, Per Morten; Bates, Shannon M.