Practical Research 1 Lesson 9 Scope and delimitation.pptx
Causal pluralism and medical diagnosis
1. Causal pluralism and
medical diagnosis
Federica Russo
Philosophy & ILLC, University of Amsterdam
Science&Technology Studies, University College London
http://russofederica.wordpress.com | @federicarusso
2. Overview
• Phil Med
• From ethics to methodology (and back)
• Relocating evidence
• Evidential pluralism in the framework of causal pluralism
• The causal challenges of medical diagnosis: a causal mosaic approach
• Zoom in: technological construction of diagnostic tests
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4. From ethics to methodology
Originally, Phil Med is about the ethical challenges arising in the field
Gradually, and since the early 2000s, Phil Med has opened up to
questions about methodology
As we speak, philosophers of science working on Medicine increasingly
discuss methodology and epistemology with ethics
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6. Causes and effects of health and disease
C causes E
Red meat consumption causes cancer
Breathing glyphosate causes cancer
Statins lower cholesterol
Exercising reduces cardiovascular disease
…
How do we know that?
What makes a causal claim true /versus/ What evidence supports a causal claim
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7. Evidential pluralism
To establish a causal claim we need multiple sources of evidence:
That C makes a difference to E
Correlations, counterfactuals, …
That C produces E
Mechanisms, processes, …
A collaborative enterprise:
Russo & Williamson >> Clarke, Gillies, Illari, Russo, Williamson >> EBM+ >> …
Perspectives: historical, practical, underexplored areas (e.g. sport studies), …
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9. A plurality of causes
Phil Med in the Philosophy of Science in Practice tradition:
“medicine” in the broadest possible terms to include all clinical, scientific, and political
forms of engagement with health and disease”
“our medicine is a disunion, with the consequence that our definition might well
include forms of practice that not all would recognize as medicine in some more
restrictive way”
Epidodes of medical causation show that even if we can formulate a problem
as “Does C cause E?”, they rarely reduce to this exact formulation
How to make justise to the variety and diversity of ways of understanding,
studying, establishing causal relations in medicine?
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12. 5 philosophical questions
Metaphysics
What is causality? What kind of things are
causes and effects?
Semantics
What does it mean that A causes B?
Epistemology
What notions guide causal reasoning?
Methodology
How to establish whether A causes B? Or
how much of A causes B?
Use
What to do once we know that A causes B?
5 scientific problems
Inference
Does A cause B? To what extent?
Prediction
What to expect if A does (not) cause B?
Explanation
How does A cause or prevent B?
Control
What factors to hold fixed to study the
relation between A and B?
Reasoning
What considerations enter in establishing
whether / how / to what extent A causes B?
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15. Tiles for the Causal
Mosaic
…
necessary and sufficient;
levels; evidence;
probabilistic causality; counterfactuals;
manipulation and invariance; processes;
mechanisms; information; dispositions;
exogeneity; Simpson’s paradox;
regularity; variation;
action; inference;
validity; truth;
…
To be arranged by:
Philosophical Questions
Metaphysics, Semantics,
Epistemology, Methodology, Use
Scientific Problems
Inference, Prediction, Explanation,
Control, Reasoning
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16. A causal mosaic
A picture made of tiles
Each tile has a role that
Is determined by the scientific problem / philosophical question it addresses
Stands in a relation with neighbouring concepts
A causal mosaic is dynamic, partly depends on scientists’ /
philosophers’ perspectives
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18. Causal challenge Description Philosophical Question Scientific Problem
levels of causation How to infer token causes of disease from
generic knowledge.
How to generate generic medical knowledge
from token instantiations of disease and
from population level data
Epistemology
Use
Reasoning (Abduction)
Inference
Control
types of causes How to explain disease using biological and
/ or social factors
Metaphysics Explanation
Control
causal narrative How to choose the most effective way to
explain disease
- from doctor’s perspective (diagnosis,
prognosis)
- from patient’s perspective (self diagnosis)
- from different worldview perspectives
(Western medicine vs Eastern vs indigenous
knowledge)
Epistemology
Metaphysics
Explanation
Prediction
Control
evidential pluralism How to select diagnostic tests and to
combine results of several diagnostic tests
Epistemology
Use
Inference
Explanation
Control
Reasoning
construction Diagnostic tests do not always give direct
epistemic access to the ‘disease’
phenomenon, but involve an element of
(technological) construction (e.g. x-rays,
FMRI, …)
Epistemology
Metaphysics
Inference
Reasoning
Explanation
definition of disease How to disentangle symptoms, causes,
effects …
Semantics
Metaphysics
Inference
Control
Reasoning 18
20. What nobody would disagree with
There is a whole range of diagnositc tests
Diagnositic tests involve analysis through instruments of various
degrees of sophistication
A simple termother
…
A Positron emission tomography
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21. What we often forget
From the simple termomether to the sophisticated PET scan, diagnosis
involves elements of construction
Epistemic
Technological
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22. The technological construction of diagnosis
Epistemology, Metaphysics
Gathering evidence to establish some
causal claim
Confront symptoms and evidence with
generic medical knowledge
What causes disease
Inference, reasoning, explanation
Inferring causes from effects
Inferring causal relations in the single
case from generic medical knowledge /
protocols
Supporting causal reasoning with
evidence
Explaining symptoms
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24. Recalibrating certainty
How certain are scientific claims / results?
And for the matter, claims about diagnosis
How to walk the thin line between
We know that we can’t claim absolute certainty (see history of science)
We do have some basis to make decision and take action (however fallible and
uncertain)
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25. Returning the argument on its head?
Phil Sci / Phil Med
Instead of talking about certaining, the ‘best’ evidence, ‘gold standards’
Consider:
How fragile is evidence and causal reasoning? What makes it so fragile? Can we distinguish
proper epistemic from sociological reasons for this fragility? …
Where to make this narrative shift?
Phil Sci / Phil Med
Science and Medicine
Doctor – Patient communication
Schools
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26. Rethinking doctor-patient communication
Convey the idea of construction, to give a sense of the difficulty of coming up with
diagnosis
See e.g. work by Annamaria Carusi & collaborators, studying interdisciplinary groups in
hospitals examining diagnostic tests
Relatedly, descronstruct the idea of certainty and of direct epistemic access to the
causes of disease and illness
Lots of work ahead for Phil Sci and Phil Tech
Regain a holistic understanding of the aetiology of health and disease
The diagnostic tests may explain part of the aetiology (the biological one), but certainly not the
whole of socio-cultural part
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28. Medical diagnosis is a fascinating and underexplored area in Phil Med
Medical diagnosis is a multifaceted form of inference from effects to
causes
By adopting the pluralistic approach of causal mosaic we can study
many of these dimensions, moving freely across ontological and
epistemological levels
By detailing the ways in which inference and reasoning are
(technologically) constructed, we are invited to re-think doctor-patient
communication, inter alia
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29. Causal pluralism and
medical diagnosis
Federica Russo
Philosophy & ILLC, University of Amsterdam
Science&Technology Studies, University College London
http://russofederica.wordpress.com | @federicarusso
Thanks for your
attention!
Notas del editor
Here sketch the way the philosophical debate has framed questions about causality, i.e. in terms of truth of causal claims. One shift consists in looking at the *evidence* that support said claims, rather than their truth.
This doesn’t mean that questions about truth are dismissed, rather they are reconceptualised (but I will not discuss in the talk, I leave it to Q&A).
If needed, background of this shift: see Illari and Russo 2014
Present evidential pluralism. An epistemological thesis. Surely, metaphysical implications (but here these are orthogonal to the argument). Instead: the epistemological thesis has, arguably, direct bearing on methods for causal assessment and for decision making.
Highlight:
The collaboration grew (Russo & Williamson >> Clarke, Gillies, Illari, Russo, Williamson >> AHRC project Evaluating Evidence in Medicine)
Consequently, the project also grew in terms of interests, perspectives, case studies, etc
Some perspectives are more historically oriented (e.g. Gillies), others more practically oriented (see e.g. Kelly, former director of NICE, UK; Straif, current head of IARC monographs )