Self-controlled studies in clinical homeopathic research.
Keywords: Homeopathy, Crossover, Epidemiology.
AbstractThe causal inference basic problem is the impossibility of comparing the effect of the exposure and the nonexposure, simultaneously, at the same individual. Hence, there are two options: examining several individuals at the same time, with analyses of the exposure and the nonexposure in different individuals (cases and controls); or evaluating the same individual at two or more points in time. The analysis of cases and controls at the same moment is the predominant situation in clinical and epidemiologic conventional research. In this study, we discuss the use of controls in homeopathy and propose the use of the subjects as their own controls, presenting some aspects of three designs that already use this approach, following the case-base paradigm: the self-controlled clinical trials and the case-crossover and case-time-control studies. We also discuss their potential for homeopathic clinical research and review proposals of statistical inference and analysis.