Uncontrolled therapeutic observations in complementary medicine—What is the benefit?

Abstract

Objective A considerable part of articles about complementary therapies focus on uncontrolled interventions administered in the context of clinical practice. According to the therapy-related hierarchy of scientific evidence 〈 http://www.cebm.net/index.aspx?o=1025 〉, however, such publications are associated with a very low evidence level. Since a perceived positive therapeutic result gained after an uncontrolled intervention may be due to at least seven factors, six of which are unspecific [2] , no conclusion can be drawn regarding a specific therapeutic effect (i.e., post hoc ergo propter hoc ). Does that mean that such reports do not have any benefit? Method A systematic search was carried out in electronic databases as well as in current textbooks on evidence-based medicine and complementary medicine. The reference lists of all relevant articles were perused. Results The identified contributions suggest that the (anecdotal) information gained in uncontrolled therapeutic interventions may indeed be valuable, particularly in (but no limited to) the following cases: • detection of possible side effect, potential new therapeutic indications, and/or problems regarding compliance [1] ; • generation of new hypotheses [3] . Discussion Vandenbroucke [3] suggested differentiating between two hierarchies of study design: one for intended effects of therapy ( cf ., 〈 http://www.cebm.net/index.aspx?o=1025 〉) and another one for discovery and studying new explanations. In the latter hierarchy, the traditional ranking of the levels of evidence is reversed: uncontrolled interventions administered in the context of clinical practice (as well as findings in patient or laboratory data and in the literature) are given the greatest importance because they may serve as catalysts for follow-up research (using the traditional hierarchy), which in turn might lead to new knowledge regarding diagnosis, therapy, and/or prevention. This double strategy may open another door towards the concept of integrative medicine.