Philosophy of Medicine
31 papers and posts.
The Pyramid Schema: The Origins and Impact of Evidence Pyramids
[This paper has been updated in 2026 from the 2022 preprint] Evidence pyramids are amongst the most recognisable artefacts of the Evidence-Based Medicine movement. Yet no study has established the origins of evidence pyramids, or analysed whether they offer any information beyond simple lists or tables. In this paper, I establish the origins of the first evidence pyramid and argue that the pyramidal turn is a retrograde step in evidence appraisal.
New publication: Grading evidence from qualitative research
Announcing a new paper co-written with a EULAR working group, reporting the findings of a systematic review of qualitative evidence appraisal tools.
Machine Evidence II: The Abstract Setting
A recent study by Gao et al. (2022) validates the warning of 'Machine Evidence' (Blunt, 2019) that language models would soon become capable of beating detection attempts by human peer reviewers. This piece looks at the near-term steps that journal editors and conference organisers can take to prevent AI-generated abstracts bypassing their screening processes, along with a warning for the long-term viability of those strategies.
[Superseded] The Pyramid Schema: The Origins and Impact of Evidence Pyramids
Evidence pyramids are amongst the most recognisable artefacts of the Evidence-Based Medicine movement. Yet no study has established the origins of evidence pyramids, or analysed whether they offer any information beyond simple lists or tables. In this paper, I establish the origins of the first evidence pyramid and argue that the pyramidal turn is a retrograde step in evidence appraisal.
Bias and the Myth of the Objective Average
Would you choose a black box AI surgeon with a 90% success rate over a human surgeon with 80% success? The answer exposes a fundamental and harmful assumption within dominant models of medical evidence.
On the Global Summit: do critiques of evidence hierarchies favour chiropractic?
The Global Summit systematic review claims that spinal manipulation therapy is not effective in preventing any non-musculoskeletal disorders. But a breakaway group has challenged their findings, in part based on my arguments regarding evidence hierarchies. Are they correct? Does my critique undermine the Global Summit review? If so, does the evidence base favour chiropractic?
Conversion Therapy: Evidence is Irrelevant
Pressure mounts upon equalities minister Kemi Badenoch to resign over the UK government's failure to ban conversion therapies. Attention has focused on the government's failure to publish research commissioned in 2018. But evidence about whether conversion therapy works is irrelevant: conversion therapy is not a medical intervention.
The True Causal Effect
Philosophy of medicine helps medical scientists to clarify their thinking. A maladept phrase like 'the true causal effect' serves to show why we need it.
Causal Relevance (Philosophy of Diagnosis, Part 3)
This series of philosophical papers unpacks six philosophical issues in diagnostics and develops a pluralistic model of diagnosis. This paper analyses the role of causal relevance in diagnostics. Are diagnoses defined by their causal relevance to symptoms?
5 years: Hierarchies of Evidence in Evidence-Based Medicine
In the five years since the publication of Hierarchies of Evidence in Evidence-Based Medicine, what has changed and what lessons can philosophers learn?
Pathognomy, Sine Qua Non and Constitutive Matching (Philosophy of Diagnosis, Part 2)
This series of philosophical papers unpacks six philosophical issues in diagnostics and develops a pluralistic model of diagnosis. This paper presents a set of minimal constraints which any theory of diagnostics must satisfy based on pathognomy and sine qua non relationships.
Problems of Diagnosis (Philosophy of Diagnosis, Part 1)
This series of philosophical papers unpacks six philosophical issues in diagnostics and develops a pluralistic model of diagnosis. This introductory paper outlines the six roles of diagnostics and distinguishes and relates the six problems of diagnosis.
Random Reflections: Cochrane and the Origins of Hierarchies
In 1972, Archie Cochrane publishedEffectiveness and Efficiency: Random Reflections on Health Services. In a little under 86 pages, Cochrane offers a wide-ranged but succinct delivery of his experience and his philosophy of evidence in clinical practice. It's a fascinating...
A Ghost of Progress - How Hierarchies Become Fixtures
I have written extensively on hierarchies of evidence in evidence-based medicine. The origin story of hierarchies of evidence is a little contentious. Several sources in EBM cite Campbell and Stanley's 1963 classic "Experimental and Quasi-experimental Designs for Research" as...
The Dismal Disease: Temozolomide and the Interaction of Evidence
Evidence interacts. To understand the evidence base for an intervention we must look not only at individual studies, but the relationships between them.
Machine Evidence: Trial by AI
Take a look at the following snippets from descriptions of clinical trials, thinking about how you'd rate the quality and strength of the evidence that comes from each:
Stop Fighting, You're Making Me SAD
Does medical science have to be adversarial to make progress? Does progress in patient care consist of weeding out treatments which are ineffective and replacing existing therapies with new and better alternatives?
Echoes of Evidence
Do you have an idea of what makes good medical evidence in your mind? Do you have ideas about the kind of evidence you’d pay attention to, and the kind of evidence you can safely disregard? Or ideas about the evidence that would strongly sway your beliefs and actions, and the...
The Authority of Evidence-Based Medicine
In the early part of the 20th century, the philosopher Ludwig Wittgenstein sought to demonstrate that metaphysical claims are meaningless. Statements which couldn’t be proven true in some way—through logic or evidence—weren’t even false, they had no meaning at all. But he ran...
The Positivity Machine: "Evidence-Based Alternative Medicine" and Grades of Recommendation
In his beat-poem Storm, the musician and comedian Tim Minchin lays out an apparent paradox. By his criteria, there can never be evidence-based alternative medicine. As soon as there’s evidence that a treatment works, it joins scientific medicine. Minchin goes on to list...
The Parachute Problem: Extracorporeal Life Support and the Demand for Trials
The United States Parachute Association recorded 120 deaths while skydiving in America in 2008-2015. Most were due to human error, while others resulted from collisions with other parachutes or aircraft. Only 5 were due to equipment failure. With around 3 million parachute...
Medicine Needs Diverse Evidence
Do not centralize evidence. If you believe that all the evidence you need to make your decisions is of a single kind, you will be so much easier to mislead. Those who say 'I’ll believe it when I see this kind of study’, once their singular preference is declared, are so much...
Two Reactions to Philosophy in Medicine
I spend a lot of my time talking to healthcare practitioners of all kinds about evidence, formally and informally. I'm mostly focused on getting the word out that RCT results are not the only thing that matters in treatment recommendations, that hierarchies of evidence are...
The Avoidable Scandal: Benoxaprofen and Theories of Medical Evidence
Benoxaprofen, marketed as Opren in the UK, created a scandal in 1982 when it was withdrawn from sale amidst reports of over 60 deaths and thousands of adverse reactions. The question of who was at fault for this disaster has been addressed many times in the academic...
UBL and Variation
I've argued that information about variation in treatment effects is vital for doctors, patients and regulators alike. This information does not come from RCTs. Nonetheless, we can acquire high-quality, compelling evidence of variation. The case studies I've presented in the...
Failures of Diagnosis
Of late, a confusion has emerged in the diagnostic and philosophical literature concerning the ways in which diagnostic failure can occur. It's rare to see clear attempts at a taxonomy of diagnostic failure. Here, I want to disambiguate a number of ways in which clinicians...
Against "Effective Treatments"
I am agitating for philosophers of medicine and philosophically-minded clinicians to lead the charge against the term “effective treatment”. This phrase has become ubiquitous in the medical and philosophical literature. But it is a misguided choice which misleads the public...
Two Dogmas of Evidence Hierarchies
Hierarchies of evidence in Evidence-Based Medicine (EBM) come in many varieties and have been very influential in medical practice and policy since the late 1990s. However, two fundamental problematic assumptions underpin the use of hierarchies of any kind in clinical...
Strength of Recommendation - the Rudner Problem
Strength of Recommendation hierarchies such as SORT and GRADE go a step further than your standard hierarchy of evidence. Standard hierarchies tend to rank or rate the evidence provided by a study on a scale of quality, strength or validity. Strength of Recommendation...
The Disunity of Evidence-Based Medicine
Critics and advocates alike have expended much effort defining Evidence-Based Medicine. However, there has been little consensus about what “Evidence-Based Medicine” is. Some authors see ‘EBM’ as something one believes—a view about medicine. Others interpret EBM as something...
RCTs - a note on terminology
For the most part, when I'm talking about an RCT, it's understood as a Randomised Clinical Trial, though I use them interchangeably because I can get away with it - but not everyone can.