Gordon H. Guyatt
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guyattgh.bsky.social
Gordon H. Guyatt
@guyattgh.bsky.social
73 followers 15 following 68 posts
Promoting use of the best evidence and patient values and preferences to inform optimal clinical and health policy decisions.
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guyattgh.bsky.social
#JAMA editor Drummond Rennie who died recently acted as the champion of the JAMA Users’ Guides to the Medical Literature. Without his advocacy the series would never have happened and the #EBM movement might never have got off the ground.

jamanetwork.com/journals/jam...
Remembering Drummond Rennie—Champion of Integrity in Science and Scientific Publication
Drummond Rennie, physician, scientist, editor, climber, tireless promoter of integrity and transparency in science, and mentor to many, died on September 12, 2025, at the age of 89.
jamanetwork.com
November 13, 2025 at 1:53 AM
guyattgh.bsky.social
When to give #RBCtransfusion for hospitalized patients with #anemia: Definitive updated trustworthy #guidelines, #JAMA publication.

pubmed.ncbi.nlm.nih.gov/37824153/
Red Blood Cell Transfusion: 2023 AABB International Guidelines - PubMed
It is good practice to consider overall clinical context and alternative therapies to transfusion when making transfusion decisions about an individual patient.
pubmed.ncbi.nlm.nih.gov
November 13, 2025 at 1:51 AM
guyattgh.bsky.social
In this one minute tutorial, I explain the meaning and significance of a weak or conditional #GRADE recommendation.

www.linkedin.com/feed/update/...
#grade | Gordon Guyatt
In this one minute tutorial, I explain the meaning and significance of a weak or conditional #GRADE recommendation. Leticia Kawano-Dourado, MD, PhD
www.linkedin.com
November 10, 2025 at 10:53 AM
guyattgh.bsky.social
Anyone interested in determining the effect of a drug in a single patient by conducting a #RandomizedTrial in a that patient – an N of 1 trial – will find this step-by-step guide enormously useful.

www.cmaj.ca/content/139/...
A clinician's guide for conducting randomized trials in individual patients
In determining optimal treatment for a patient conventional trials of therapy are susceptible to bias. Large-scale randomized trials can provide only a partial guide and have not been or cannot be car...
www.cmaj.ca
November 6, 2025 at 11:57 AM
guyattgh.bsky.social
If you are using #GRADE to rate #CertaintyofEvidence for diagnostic tests this article that deals with study design, #RiskofBias, and #indirectness provides crucial guidance.

pubmed.ncbi.nlm.nih.gov/32060007/
GRADE guidelines: 21 part 1. Study design, risk of bias, and indirectness in rating the certainty across a body of evidence for test accuracy - PubMed
Rating the certainty of a body of evidence using GRADE in Cochrane and other reviews and World Health Organization and other guidelines dealing with in TA studies helped refining our approach. The resulting guidance will help applying GRADE successfully for questions and recommendations focusing on …
pubmed.ncbi.nlm.nih.gov
November 6, 2025 at 11:56 AM
guyattgh.bsky.social
Just published #MetaAnalysis of #AdverseEffects of short-course #steroids in #children and #adolescents in many diseases can provide high certainty evidence for their use in #RareDisease. Generally applicable approach for harms of common drugs in rare diseases.

pubmed.ncbi.nlm.nih.gov/41026484/
Adverse Events Following Short-Course Systemic Corticosteroids Among Children and Adolescents: A Systematic Review and Meta-Analysis - PubMed
In this systematic review and meta-analysis of randomized trials, there was moderate certainty evidence that corticosteroids were associated with an increased risk of hyperglycemia and sleep problems and low certainty evidence that corticosteroids were associated with increased risk of gastrointesti …
pubmed.ncbi.nlm.nih.gov
November 3, 2025 at 4:24 AM
guyattgh.bsky.social
Forming #EvidenceBased plans of #EBM care that respond to each patient’s situation demands #SharedDecisionMaking. JP Brito, Iris Hargraves, and Marleen Kunneman are doing leading work to advance the practice of making care fit using shared decision making.

ebm.bmj.com/content/28/4...
Shared decision-making as a method of care
Care happens in interaction between the patient and the clinician, in conversation where the patient and clinician uncover or develop a shared understanding of the problematic situation of the patient...
ebm.bmj.com
November 3, 2025 at 4:23 AM
guyattgh.bsky.social
This video presents a answer to the question of how evidence-based medicine - #EBM - protects us against inflated, misleading claims of treatment effect. I’ll be posting a number of such snippets and you’ll enjoy my charming interlocutor,
@leticiakawano.bsky.social
www.linkedin.com/feed/update/...
#evidencbasedmedicine #ebm | Gordon Guyatt
This video presents a 16 second answer to the question of how #EvidencBasedMedicine - #EBM - protects us against inflated, misleading claims of treatment effect. I’ll be posting a number of such snipp...
www.linkedin.com
November 3, 2025 at 4:22 AM
guyattgh.bsky.social
The ground-breaking #NEJM #randomizedTrial suggests that every #surgery patient at substantial #bleeding risk should receive #tranexamicAcid: 24% #RelativeRisk reduction in serious bleeding.

www.nejm.org/doi/full/10....
Tranexamic Acid in Patients Undergoing Noncardiac Surgery | NEJM
Perioperative bleeding is common in patients undergoing noncardiac surgery. Tranexamic acid is an antifibrinolytic drug that may safely decrease such bleeding. We conducted a trial involving patien...
www.nejm.org
October 28, 2025 at 5:19 AM
guyattgh.bsky.social
15 minute #JAMA podcast in which I interview world authority @thomasagoritsas.bsky.social on how to Use a Patient Management #Recommendations: #ClinicalPracticeGuidelines and #DecisionAnalyses

edhub.ama-assn.org/jn-learning/...
edhub.ama-assn.org
October 22, 2025 at 1:49 PM
guyattgh.bsky.social
This #BMJ article demonstrates that plausible assumptions regarding outcomes of patients lost to follow-up could often change the interpretation of results of #RandomisedControlledTrials published in top medical journals.

pubmed.ncbi.nlm.nih.gov/22611167/
Potential impact on estimated treatment effects of information lost to follow-up in randomised controlled trials (LOST-IT): systematic review - PubMed
Plausible assumptions regarding outcomes of patients lost to follow-up could change the interpretation of results of randomised controlled trials published in top medical journals.
pubmed.ncbi.nlm.nih.gov
October 22, 2025 at 5:54 AM
guyattgh.bsky.social
Are #RelativeRisks overwhelmingly similar across risk groups? And if so, can we personalize care by applying relative risk to individual patients’ risk profiles? This key #EBM study demonstrates that the answer to both questions is an unquestionable YES.
pubmed.ncbi.nlm.nih.gov/11914297/
Can we individualize the 'number needed to treat'? An empirical study of summary effect measures in meta-analyses - PubMed
The fixed effects OR, random effects OR and random effects RR appear to be reasonably constant across different baseline risks. Given the interpretational and arithmetic ease of RR, clinicians may wis...
pubmed.ncbi.nlm.nih.gov
October 20, 2025 at 3:56 AM
guyattgh.bsky.social
A survey addresses #guidelines trustworthiness evolution 2010 to 2022. Glass half empty - modest improvement, long way to go; and half full - almost 20% high trustworthiness. Thousands published yearly, astute clinicians will find quality guidelines relevant to them
pubmed.ncbi.nlm.nih.gov/40889618/
Trustworthiness of treatment clinical practice guidelines has modestly improved since the introduction of Institute of Medicine standards: a systematic survey - PubMed
As assessed by the modified NEATS instrument, although trustworthiness of treatment guidelines has improved after the introduction of IOM standards, improvements proved modest and post-IOM guidelines ...
pubmed.ncbi.nlm.nih.gov
October 20, 2025 at 3:56 AM
guyattgh.bsky.social
Studies being published checking whether #LLMs and other #generativeAI models provide good health advice. #Clinicians, #Researchers, #Reviewers, #Editors, #Publishers can check and optimize studies through the #CHART checklist, abstract checklist, and methodological diagram.
chartguideline.org
CHART - Chatbot Assessment Reporting Tool
CHART: A comprehensive reporting guideline for Chatbot Health Advice studies
chartguideline.org
October 20, 2025 at 3:54 AM
guyattgh.bsky.social
When applying plausible assumptions to the outcomes of participants with definite missing data to 100 #SystematicReviews, the average change in pooled relative effect estimate was substantive.

#BMJ #EBM #Medicine

pubmed.ncbi.nlm.nih.gov/32847800/
Potential impact of missing outcome data on treatment effects in systematic reviews: imputation study - PubMed
Even when applying plausible assumptions to the outcomes of participants with definite missing data, the average change in pooled relative effect estimate is substantive, and almost a quarter (22%) of...
pubmed.ncbi.nlm.nih.gov
October 13, 2025 at 6:37 AM
guyattgh.bsky.social
My research of #GenderAffirming care following #EBM principles have engendered attacks by trans activists, anti-trans activists, and journalists advocating denial of gender-affirming care. Fortunately, some journalists present a balanced account. Here is one.
www.statnews.com/2025/09/22/e...
Author of reviews of gender affirming care decries ‘egregious misuse’ of the findings to justify bans
Gordon Guyatt, a co-author of systematic reviews of gender-affirming care, calls use of the findings to justify banning care "egregious."
www.statnews.com
October 10, 2025 at 2:37 AM
guyattgh.bsky.social
Recently completed biking vacation with Maureen in Portugal. It’s a wonderful country!
October 10, 2025 at 2:36 AM
guyattgh.bsky.social
Pooling health-related #QualityofLife outcomes in #MetaAnalysis in ways that enhance #interpretability provides a big challenge. This tutorial shows you the statistical methods for achieving the goal.

pubmed.ncbi.nlm.nih.gov/26061786/
Pooling health-related quality of life outcomes in meta-analysis-a tutorial and review of methods for enhancing interpretability - PubMed
- The use of these approaches may enhance the interpretability and the usefulness of systematic reviews involving HRQL outcomes. Copyright © 2011 John Wiley & Sons, Ltd.
pubmed.ncbi.nlm.nih.gov
October 10, 2025 at 2:35 AM
guyattgh.bsky.social
#GRADE’s primary focus in #SystematicReviews has been on rating certainty in evidence on interventions. But in this article GRADE also provides guidance for #CertaintyofEvidence in #prognosis in which #ObservationalStudies start as high certainty evidence.

pubmed.ncbi.nlm.nih.gov/31982539/
GRADE Guidelines 28: Use of GRADE for the assessment of evidence about prognostic factors: rating certainty in identification of groups of patients with different absolute risks - PubMed
The same principles GRADE proposed for bodies of evidence addressing treatment and overall prognosis work well in assessing individual prognostic factors, both in noncontextualized and contextualized ...
pubmed.ncbi.nlm.nih.gov
October 1, 2025 at 11:32 PM
guyattgh.bsky.social
At the recent #GuidelinesInternationalNetwork (GIN) meeting in Geneva I paid the price for my notoriety as folks cornered me, including this group lining up to have their photo taken with me.
October 1, 2025 at 11:31 PM
guyattgh.bsky.social
At recent #GuidelinesInternationalNetwork (GIN) meeting with Thomas Agoritsas, Chair of the #MAGICEcosytemFoundation and international #GRADE methodology leader and our researcher Prashanti Eachempati, creator of the JUDGE instrument that will revolutionize GRADE education and practice.
September 26, 2025 at 3:12 PM
guyattgh.bsky.social
The #ChronicRespiratoryQuestionnaire (CRQ) is the most responsive and valid #HealthStatusMeasurement instrument for disease-specific #QualityOfLife in patients with #COPD and other chronic respiratory conditions. This paper presents a self-report version.

pubmed.ncbi.nlm.nih.gov/11713359/
Development of a self-reported Chronic Respiratory Questionnaire (CRQ-SR) - PubMed
The CRQ-SR is a reproducible, reliable, and stable measure of health status. It compares well with the CRQ-IL but cannot be used interchangeably. The main advantage of the CRQ-SR over the CRQ-IL is th...
pubmed.ncbi.nlm.nih.gov
September 26, 2025 at 3:32 AM
guyattgh.bsky.social
Clinicians increasingly rely on #chatbots for advice in managing patients. But is this advice helpful or misleading? Researchers are trying to find out. A survey of 137 studies of bot performance demonstrates their methods leave a great deal to be desired.
pubmed.ncbi.nlm.nih.gov/39903463/
Large Language Models for Chatbot Health Advice Studies: A Systematic Review - PubMed
In this systematic review of 137 chatbot health advice studies, the reporting quality was heterogeneous and may inform the development of the CHART reporting standards. Ethical, regulatory, and patien...
pubmed.ncbi.nlm.nih.gov
September 22, 2025 at 3:13 PM
guyattgh.bsky.social
I am keen that the Core #GRADE series - 7 articles in
@bmj.com this spring - gets optimal use. I will therefore be available to address queries anyone has about using Core GRADE. Don’t hesitate to ask at guyatt@mcmaster.ca.

pubmed.ncbi.nlm.nih.gov/40233981/
Why Core GRADE is needed: introduction to a new series in The BMJ - PubMed
Why Core GRADE is needed: introduction to a new series in The BMJ
pubmed.ncbi.nlm.nih.gov
September 22, 2025 at 3:23 AM
guyattgh.bsky.social
#TransActivists suggest our #SystematicReviews showing low certainty evidence for outcomes of #GenderAffirming care are “pseudoscientce”. The right attacks because we suggest that banning trans care is unconscionable. This newspaper article provides a balanced perspective.
archive.ph/WsBIN
archive.ph
September 22, 2025 at 3:19 AM