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Gordon H. Guyatt

@guyattgh.bsky.social

65 followers 15 following 50 posts

Promoting use of the best evidence and patient values and preferences to inform optimal clinical and health policy decisions.

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Gordon H. Guyatt @guyattgh.bsky.social · 6d

#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

Gordon H. Guyatt @guyattgh.bsky.social · 6d

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.

Gordon H. Guyatt @guyattgh.bsky.social · 12d

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.

Gordon H. Guyatt @guyattgh.bsky.social · 12d

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

Gordon H. Guyatt @guyattgh.bsky.social · 16d

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

Gordon H. Guyatt @guyattgh.bsky.social · 16d

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 [email protected].

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

Gordon H. Guyatt @guyattgh.bsky.social · 16d

#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

Gordon H. Guyatt @guyattgh.bsky.social · 23d

#GRADE provides guidance for rating #CertaintyofEvidence regarding accuracy of diagnostic tests. This informative paper provides details on assessing #inconsistency, #imprecision, #PublicationBias and other domains and for creating #SummaryofFindings tables.

pubmed.ncbi.nlm.nih.gov/32058069/

GRADE guidelines: 21 part 2. Test accuracy: inconsistency, imprecision, publication bias, and other domains for rating the certainty of evidence and presenting it in evidence profiles and summary of f...

Using GRADE in Cochrane and other reviews as well as World Health Organization and other guidelines helped refining the GRADE approach for rating the certainty of a body of evidence from TA studies. A...

pubmed.ncbi.nlm.nih.gov

Gordon H. Guyatt @guyattgh.bsky.social · 25d

Most #GRADE users are familiar with GRADE’s #EvidenceToDecision frameworks for interventions. Less so with EtD for tests. This excellent exposition provides guidance when creating or using a #DiagnosticTests and other tests (such as #screening) EtDs.

pubmed.ncbi.nlm.nih.gov/26931285/

GRADE Guidelines: 16. GRADE evidence to decision frameworks for tests in clinical practice and public health - PubMed

EtD frameworks for developing recommendations and making decisions about tests lay out the sequential steps in reviewing and assessing the different types of evidence that need to be linked.

pubmed.ncbi.nlm.nih.gov

Gordon H. Guyatt @guyattgh.bsky.social · 26d

Our group posted: using our #GRADE #SR of #GenderAffirming care to justify denial of care is unconscionable. A #NationalPost piece decried our position. The author had been suspended by the BC College of Nursing for comments derogatory towards transgender people!
nationalpost.com/opinion/fath...

Amy Hamm: Father of 'evidence-based medicine' turns his back on science

Bullied by activists, Gordon Guyatt is now arguing against using his own findings to guide policy

nationalpost.com

Gordon H. Guyatt @guyattgh.bsky.social · 28d

As winner of the 2024 Canadian #Friesen prize, I toured 8 Canadian universities delivering Friesen lectures on the past and future of #EvidenceBasedMedicine. A booklet summarizing the lecture is now available.

fchr.ca/books

Milestone 20th year of The Henry G. Friesen International Prize in Health Research

Gordon H. Guyatt @guyattgh.bsky.social · 28d

This classic article looking at #DiagnosticTests for iron deficiency #anemia (showed #ferritin by far the best) remains the best example to teach students how to use #LikelihoodRatios in their clinical practice.

pubmed.ncbi.nlm.nih.gov/2178409/

Diagnosis of iron-deficiency anemia in the elderly - PubMed

Thirty-six percent of our patients had no demonstrable marrow iron and were classified as being iron-deficient. The serum ferritin was the best test for distinguishing those with iron deficiency from ...

pubmed.ncbi.nlm.nih.gov

Gordon H. Guyatt @guyattgh.bsky.social · Sep 4

How the world has changed, how quickly we take for granted technological miracles that not so long ago would have been the stuff of #ScienceFiction. Only few years ago, a colleague called his research fellow over to view the miracle of his computer screen that showed six talking faces. And now…

Gordon H. Guyatt @guyattgh.bsky.social · Sep 2

#TransitionRatings (are you better; if so how much) is the most-used strategy for establishing #MinimalImportantDifferences in #PatientReportedOutcomeMeasures. But transition ratings must be valid. This seminal, essential paper shows how to test their validity.
pubmed.ncbi.nlm.nih.gov/12393078/

A critical look at transition ratings - PubMed

Patient ratings of the extent to which they have improved or deteriorated-transition ratings-are extremely common in clinical practice and clinical research. However, some have raised concerns about t...

pubmed.ncbi.nlm.nih.gov

Gordon H. Guyatt @guyattgh.bsky.social · Aug 31

Hanlon's Razor is a principle stating, "Never attribute to malice that which is adequately explained by incompetence". I’ve recently had an experience that put me in mind of these wise words – I suspected malevolence; explanation proved otherwise.

fs.blog/mental-model...

Hanlon's Razor: Not Everyone is Out to Get You

Hanlon’s razor is a mental safeguard against the temptation to label behavior as malicious when incompetence is the most common response

Gordon H. Guyatt @guyattgh.bsky.social · Aug 31

We chose the term #MinimalClinicallyImportantDifference in an era of medical paternalism. We subsequently realized that we are considering patient-important outcomes and our language should align. This article presents the transition to #MinimallyImportantDifference
pubmed.ncbi.nlm.nih.gov/15762909/

Commentary--goodbye M(C)ID! Hello MID, where do you come from? - PubMed

Commentary--goodbye M(C)ID! Hello MID, where do you come from?

pubmed.ncbi.nlm.nih.gov

Gordon H. Guyatt @guyattgh.bsky.social · Aug 26

Legislators have unconscionably misused our #SystematicReviews of #GenderTransition interventions to deny #PatientsCare. Formerly, I thought my job ended with conducting and reporting high quality research. I now realize I have an additional responsibility to address how my work is used.

Gordon H. Guyatt @guyattgh.bsky.social · Aug 26

The #GRADE evidence to decision (EtD) framework provides invaluable guidance in moving from evidence to recommendations. There are a number of variations for specific areas. This article explains EtD frameworks for #HealthSystem and policy decisions.
pubmed.ncbi.nlm.nih.gov/29843743/

The GRADE Evidence to Decision (EtD) framework for health system and public health decisions - PubMed

This framework provides a structured and transparent approach to support policy-making informed by the best available research evidence, while making the basis for decisions accessible to those whom t...

pubmed.ncbi.nlm.nih.gov

Gordon H. Guyatt @guyattgh.bsky.social · Aug 21

Recent BMJ: strong rapid recommendation against lucrative interventional #pain intervention. Practitioners pushed back, but this enlightened exception acknowledges industry influence, catchy branding ignoring science, hidden COI, low quality research.

pmc.ncbi.nlm.nih.gov/articles/PMC...

A Call for Reckoning and Reform in Interventional Pain Medicine and Neuromodulation Research

pmc.ncbi.nlm.nih.gov

Gordon H. Guyatt @guyattgh.bsky.social · Aug 21

As this article demonstrates, when one is creating a health status measurement #instrument for use in #Clinicaltrials, factor analysis has major limitations. Far preferable to pick items patients think are important than to choose on the basis of factor structure.
pubmed.ncbi.nlm.nih.gov/9120521/

Clinical impact versus factor analysis for quality of life questionnaire construction - PubMed

Although some items were the same for both methods, there were also some important differences. Different approaches to item reduction led to appreciably different instruments.

pubmed.ncbi.nlm.nih.gov

Gordon H. Guyatt @guyattgh.bsky.social · Aug 14

Explanatory or mechanistic #RCTs of physical or psychological interventions requires “placebo,” or “sham” comparators. This @bmj.com article presents recommendations for designing, and reporting comparator interventions as well as a reporting checklist.
pubmed.ncbi.nlm.nih.gov/37230508/

Recommendations for the development, implementation, and reporting of control interventions in efficacy and mechanistic trials of physical, psychological, and self-management therapies: the CoPPS Stat...

Recommendations for the development, implementation, and reporting of control interventions in efficacy and mechanistic trials of physical, psychological, and self-management therapies: the CoPPS Stat...

pubmed.ncbi.nlm.nih.gov

Gordon H. Guyatt @guyattgh.bsky.social · Aug 11

Over-reliance on #SurrogateOutcomes remains a big problem in expert-driven recommendations. This #JAMA users guide shows how most surrogates are not valid: in #RCTs they fail to predict impact of interventions on patient-important outcomes
pubmed.ncbi.nlm.nih.gov/10463714/

Users' guides to the medical literature: XIX. Applying clinical trial results. A. How to use an article measuring the effect of an intervention on surrogate end points. Evidence-Based Medicine Working...

Users' guides to the medical literature: XIX. Applying clinical trial results. A. How to use an article measuring the effect of an intervention on surrogate end points. Evidence-Based Medicine Working...

pubmed.ncbi.nlm.nih.gov

Gordon H. Guyatt @guyattgh.bsky.social · Aug 7

Introducing #CHART - reporting guidelines for studies evaluating evidence summaries and health advice from #genAI models like #ChatGPT.

Authors may apply the CHART checklist ✅and methodological diagram 📈 when reporting their studies.

Published in @bmj.com: pubmed.ncbi.nlm.nih.gov/40750271/

Reporting guidelines for chatbot health advice studies: explanation and elaboration for the Chatbot Assessment Reporting Tool (CHART) - PubMed

Reporting guidelines for chatbot health advice studies: explanation and elaboration for the Chatbot Assessment Reporting Tool (CHART)

pubmed.ncbi.nlm.nih.gov

Gordon H. Guyatt @guyattgh.bsky.social · Aug 2

#GRADE uses optimal information size (number of patients in a power calculation of individual #RCTs to detect a modest effect), to decide on credibility of #MetaAnalyses showing large effects. This simulation study provides powerful support for GRADE’s OIS approach.
pubmed.ncbi.nlm.nih.gov/22028777/

The number of patients and events required to limit the risk of overestimation of intervention effects in meta-analysis--a simulation study - PubMed

Random errors are a frequent cause of overestimation of intervention effects in meta-analyses. Surpassing the optimal information size will provide sufficient protection against overestimation.

pubmed.ncbi.nlm.nih.gov

Reposted by Gordon H. Guyatt

The BMJ @bmj.com · Jul 30

"Evidence itself never gives us the answer what to do. It's evidence in the context of values and preferences."

Professor Gordon Guyatt talks to The BMJ about the challenges of evidence based medicine and introduces the Core GRADE system @guyattgh.bsky.social
www.youtube.com/watch?v=433J...

GRADE the trustworthiness of evidence | Prof. Gordon Guyatt

YouTube video by The BMJ

www.youtube.com