Confirmation and confirmation bias: The role of prognostic factor research

Abstract

Background: Some homoeopathic practitioners fear that prognostic factor research (PFR) of homoeopathic symptoms neglects the context of these symptoms. Materials and Methods: The function of repertory and materia medica in the homoeopathic method is discussed. Previous research shows how the repertory can be improved. Outcome and Discussion: The homoeopathic procedure can be divided into two stages: an open mind stage to make an inventory of all possible medicines and a confi rmatory stage to select the medicine that fi ts the totality. Closing the open mind stage too soon will cause confi rmation bias. PFR is meant to improve the repertory in several aspects. Bayes’ theorem provides an algorithm for homoeopathy and the inherent likelihood ratio (LR) a generalisation of Hahnemann’s aphorism 153 to a broad differentiation of importance of symptoms arranged by peculiarity and by prevalence in respective medicine populations. Conclusion: PFR does not alter the way we select homoeopathic medicines, but it improves the repertory. LR generalises Hahnemann’s aphorism 153 to an algorithm that distinguishes a large range of symptoms, peculiar and less peculiar, according to their importance for the choice of a medicine.