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