How should homeopathy be assessed? Still applying conventional science Lex Rutten, the Netherlands.
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Transcript of How should homeopathy be assessed? Still applying conventional science Lex Rutten, the Netherlands.
How should homeopathy be assessed?
Still applying conventional science
Lex Rutten, the Netherlands
Belief or science
Belief: conventional medicine works; homeopathy does not.
Homeopathy cannot succeed in Randomised Controlled Trial
Scientific mirror
Homeopathy - conventional medicine: same results in RCT
Hypothesis: selection bias, low quality, heterogeneity
Shang, the Lancet aug. 2005
RCT works only for conventional medicine (????)
• Allen Roses (GSK, December 2003):90% of conventional medicines work in 30-50% of all patients
• Pharmacogenetics: not only the disease, but the whole person: genotype
• Homeopathy: same, but phenotype
‘It works’ doesn’t mean it works
Why not 100% success?
diagnosisRCT
co-morbidity
side-effects
circumstancestherapy-result
Unreal certainty
From complaint towards result
symptom A
symptom B
test X
test Y
diagnosis result
diagnostic research
probability of diagnosis
RCT
chances placebo < 0.05
Homeopathic ‘diagnosis’
Diagnosis Result
Diagnosis
Diagnostic/prognostic researchDiagnostic/prognostic research
Probability of resultProbability of result
symptom A
symptom B
symptom C
symptom D
Effect modification
comorbidity
age > 65
sex
social status
Result
Diagnostic/prognostic researchDiagnostic/prognostic research
Probability of resultProbability of resultsuicidal?
Bayes method
• Knowledge from experience
• Direct results in practice
• Handling of complex clinical symptoms
• Probability instead of certainty
• Step-by-step increasing certainty by adding data
Bayes and homeopathy
• More symptoms more certainty
• Peculiar symptoms are more important
• Vagueness is no problem
• Disadvantage: difficult calculations (use a calculator)
Likelihood Ratio (LR)
LR+ =Occurrence in target population
Occurrence in rest-population
Odds = chance / (1-chance)
Chance = odds / (1+odds)
Bayes’ rule: posterior odds = LR x prior odds
Prior to posterior chance (LR+=5)
Prior chance• 1%• 10%• 30%• 50%• 80%
Posterior chance
4.8%
35.7%
68.1%
83.3%
95.2%
Homeopathic diagnosis stepwise
Lachesis in menopausal complaints
symptom LR success (%)
1. menopause 10%?
2. loquacity 5 35%
3. left-sided complaints 3? 62%
4. clothing < 3? 83%
Repertory with LR
Partly hypothetical rubric ‘Fear of death’:
Acon. , act-sp., agn. , all-s, ..., Anac. , apis , arg-n. ,Ars. , asaf., aur. , ... Calc. ,lach. , Lat-m. , led., ...
FEAR- Death, of: in general, more than expected considering circumstances;occurring almost daily. Prevalence 5% (±0.5)
(6)
(4) (2.5) (3)(1)(6)
(3)
(3.5)(2)
(13)
Practical homeopathic research
• Relation between symptom and success
• No conflict with daily practice
• Takes a few seconds during each consultation
• Outcome: a reliable repertory
Prospective research
• Check the presence of 6 symptoms in each new patient
• Keep record of medicines and results
• a=occurrence of symptom in Lachesis-population
• b=occurrence of symptom in rest-population
• Likelihood Ratio = a / b
A few seconds of each consultation
Results fear of death
medicine fear death, n= medicine population,n=
LR+
Anacardium 2 4 13.36Arsenicum album 2 8 6.66Calcarea carbonica 2 27 1.95
Repertory: Anac., Ars., Calc.
Fear of death in whole population: 3.8%
Does this lead us to a more reliable repertory?
medicine LR+
Diarrhea anticip. arg-n. 15
calc. 2.2
ph-ac 10
Grinding teeth bell. 6.1
carc. 2.6
merc. 5
tub. 7.3
Results after 15 months, n=1634
medicine LR+
Sens. injustice bell. 3.4
caust. 6
Loquacity hyos. 7.8
lach. 4.7
Lachesis in menopausal complaints
• LR+ loquacity - Lachesis = 5 (1,8-12,3)
• succes by Lachesis in menopausal complaints with loquacity goes from 10%(?) to 35%.
Dear GP,
Treat your most loquacious patients with menopausal complaints with Lachesis
Conclusions
• Homeopathy (and conventional medicine) is bayesian science
• LR research is easy, cheap and rewarding
• Effectiveness of homeopathy can be much improved by LR research
Vagueness
herpeslips
0,00%
2,00%
4,00%
6,00%
8,00%
10,00%
12,00%
14,00%
1 2 3 4 5 6 7 8 9
doctor
herpes=1
herpes=2
loquacity
0,00%
5,00%
10,00%
15,00%
20,00%
25,00%
30,00%
1 2 3 4 5 6 7 8 9
doctor
loquax=1
loquax=2
Herpes lip Loquacity