Hahnemann and the methodology of pathogenetic trials in healthy volunteers: a reappraisal

Abstract

This article assesses the guidelines and protocols that Hahnemann developed for homeopathic pathogenetic trials (HPTs) - often referred to as proving - and reappraise them in the light of more recent knowledge and protocols for clinical trials involving human subjects. Innovative features and methods introduced by Hahnemann and aimed at reducing bias are noted. A number of features which are now known to lead to bias in trials and which may be included in the reporting of symptoms are discussed in relation to HPTs. These features include: absence of control groups, absence of random allocation, absence of blinding, the inclusion of trivial and pre-existing symptoms, the inclusion of well-known acquaintances as trial participants, and the lack of definition of the healthy state. Advice from experts and papers published in recent decades related to the design of HPTs are discussed. The importance of developing methods to screen participants in HPTs for susceptibility to the tested medicine is discussed. The absence of trials meeting high quality standards in their design is highlighted. The article concludes with a plea for researchers to show the same desire for rigour and innovation that Hahnemann did in the development of HPTs, whilst fully recognising the requirements and protocols necessary for any trial of medicines on human beings, so that, as Hahnemann wanted, only reliable symptoms from HPTs will be admitted in the materia medica and clinical practice