How should homeopathy be assessed?

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. ‘It works’ doesn’t mean it works • 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

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

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

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

8. Effect modification Diagnostic/prognostic research comorbidity age > 65 Result sex social status 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 symptoms more certainty • Peculiar symptoms are more important • Vagueness is no problem • Disadvantage: difficult calculations (use a calculator)

11. Likelihood Ratio (LR) Occurrence in target population LR+ = Occurrence in rest-population Odds = chance / (1-chance) Chance = odds / (1+odds) Bayes’ rule: posterior odds = LR x prior odds

12. Prior chance 1% 10% 30% 50% 80% Posterior chance 4.8% 35.7% 68.1% 83.3% 95.2% Prior to posterior chance (LR+=5)

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

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 lip Loquacity