title: Elements of therapeutic research structure.
abstract: For the purpose of comparative therapeutic research, an overview of some basic terms and definitions is given. The main emphasis lies on the time structure of the research and the possible sources of bias and validity. In addition, methods to deal with confounding, effect modification and possible causal inferences are summarized.
authors.affiliation: Verein für Krebsforschung, Institut Hiscia, Kirschweg 9, CH-4144 Arlesheim, Switzerland. ziegler@hiscia.ch
authors.forename: R
authors.initials: R
authors.lastname: Ziegler
mesh_terms: D015982:Bias; D015331:Cohort Studies; D000529:Complementary Therapies / Q000592:standards*; D003625:Data Collection / Q000379:methods / Q000592:standards; D006801:Humans; D008137:Longitudinal Studies; D015203:Reproducibility of Results; D012106:Research / Q000592:standards*