1. Cause in Medicine HINF 371 - Medical Methodologies Session 6

2. Objective To understand the need for establishing cause of disease To understand the need for establishing cause of disease

3. Reading Montgomery K (2006) Chapter 4: “What Brings You Here Today?”: The Idea of Cause in Medical Practice in How Doctor’s Think: Clinical Judgment and Practice of Medicine, Oxford University Press, USA Montgomery K (2006) Chapter 4: “What Brings You Here Today?”: The Idea of Cause in Medical Practice in How Doctor’s Think: Clinical Judgment and Practice of Medicine, Oxford University Press, USA Mar CD, Doust J, Glasziou (2006) Chapter 3: Models of Disease, in Clinical Thinking: Evidence, Communication and Decision-Making, Blackwell Publishing and BMJ Books, USA Mar CD, Doust J, Glasziou (2006) Chapter 3: Models of Disease, in Clinical Thinking: Evidence, Communication and Decision-Making, Blackwell Publishing and BMJ Books, USA

4. Opening question Physician: What brings you here today? Physician: What brings you here today? Patient: That’s what I am here for you to find out Patient: That’s what I am here for you to find out Patient: I want to know what is going on with me and what to do about it. Patient: I want to know what is going on with me and what to do about it.

5. Importance of Cause To know the cause of disease is to have control To know the cause of disease is to have control Medicine is driven by it and patients and families are part of that drive Medicine is driven by it and patients and families are part of that drive Cause and effect establishes the science component of medicine Cause and effect establishes the science component of medicine Cause is central to the medicine’s conventional, positivist ideal of science Cause is central to the medicine’s conventional, positivist ideal of science But investigation of cause is retrospective and more like narrative investigation more like history or economics. But investigation of cause is retrospective and more like narrative investigation more like history or economics. Medicine is guilty of disguising what is not known Medicine is guilty of disguising what is not known

6. Process CauseMechanism Symptoms Cause Mechanism Symptoms Cause Promote r Self perpetuating conditions

7. Cause and decision making When the cause and effect relationship is clear treatment and decision making is straight and easy When the cause and effect relationship is clear treatment and decision making is straight and easy When it is not, then clinical reasoning is what providers depend on. When it is not, then clinical reasoning is what providers depend on. http://symptoms.webmd.com/ http://symptoms.webmd.com/ http://symptoms.webmd.com/ Investigation is from effect to cause Investigation is from effect to cause Clinical inquiry is an interpretive quest that circles between biology and epidemiology on the one hand and clinical signs of illness on the other. Clinical inquiry is an interpretive quest that circles between biology and epidemiology on the one hand and clinical signs of illness on the other.

8. Culture effects cause and effect Four humours Four humours Chiropractic, osteopathy, and Alexander Method Chiropractic, osteopathy, and Alexander Method Homeopathy Homeopathy Spirit possession, evil humours and divine intervention Spirit possession, evil humours and divine intervention

9. Other cause and effect models HumourSeasonElementOrganQualit ies Ancient name ModernMBTIAncient characteristics BloodSpringAirLiver Worm and moist SanguineArtisanSP Courageous, hopeful, amorous Yellow bile SummerFire Gall bladder Warm and dry CholericIdealistNF Easily angered, bad tempered Black bile AutumnEarthSpleen Cold and dry MelancholicRationalistNT Despondent, Sleepless, Irritable PhlegmWinterWater Brain and lungs Cold and moist PhlegmaticGuardianSJ Calm, unemotional

10. Empirical disease models Dropsy – foxglove extract Dropsy – foxglove extract Fever – Quinine Fever – Quinine Scurvy – Lime juice Scurvy – Lime juice Stye (hordeolum) – garlic juice Stye (hordeolum) – garlic juice Skin infections – Oregano oil (carvacrol and thymol have potent anti-microbial properties) Skin infections – Oregano oil (carvacrol and thymol have potent anti-microbial properties) Do you have similar examples? Do you have similar examples?

11. What is a dis-ease? Primarily what is not “normal” in our times Primarily what is not “normal” in our times Extremes of normal Extremes of normal Selection criteria for a new procedure Selection criteria for a new procedure Selection criteria for a new medication Selection criteria for a new medication Risk factors Risk factors What we think it is not normal for us What we think it is not normal for us

12. Principles for Physicians 1. Understanding the mechanism of disease enables a rational approach to care 2. Patients who understand their illness may have a better platform to help themselves 3. Even if we (think we) understand a disease, we must still test any consequent management 4. Many diseases are simply extremes of the normal distribution of human characteristics. Knowing this should help 1. Patients understand their problems 2. Doctors do not chase futile ‘causes’