1. How should homeopathy be assessed? Still applying conventional science Lex Rutten, the Netherlands

2. Belief or science Belief: conventional medicine works; homeopathy does not. Homeopathy cannot succeed in Randomised Controlled Trial

3. 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 (????)

4. 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

5. Why not 100% success? diagnosis RCT co-morbidity side-effects circumstances therapy-result Unreal certainty

6. From complaint towards result symptom A symptom B test X test Y diagnosisresult diagnostic research probability of diagnosis RCT chances placebo < 0.05

7. Homeopathic ‘diagnosis’ DiagnosisResult Diagnosis Diagnostic/prognostic research Probability of result symptom A symptom B symptom C symptom D

8. Effect modification comorbidity age > 65 sex social status Result Diagnostic/prognostic research Probability of result suicidal?

9. 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

10. Bayes and homeopathy More symptomsmore certainty Peculiar symptoms are more important Vagueness is no problem Disadvantage: difficult calculations (use a calculator)

11. 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

12. 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%

13. Homeopathic diagnosis stepwise Lachesis in menopausal complaints

14. Repertory with LR Partly hypothetical rubric ‘Fear of death’:

15. Practical homeopathic research Relation between symptom and success No conflict with daily practice Takes a few seconds during each consultation Outcome: a reliable repertory

16. 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

17. A few seconds of each consultation

18. Results fear of death Repertory: Anac., Ars., Calc. Fear of death in whole population: 3.8% Does this lead us to a more reliable repertory?

19. Results after 15 months, n=1634

21. 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

22. 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

23. Vagueness Herpes lipLoquacity