how should homeopathy be assessed?
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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. - PowerPoint PPT PresentationTRANSCRIPT
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