title: Exploratory trials, confirmatory observations: a new reasoning model in the era of patient-centered medicine.
abstract: BACKGROUND
  The prevailing view in therapeutic clinical research today is that observational studies are useful for generating new hypotheses and that controlled experiments (i.e., randomized clinical trials, RCTs) are the most appropriate method for assessing and confirming the efficacy of interventions.
  
  
  CONCLUSIONS
  The current trend towards patient-centered medicine calls for alternative ways of reasoning, and in particular for a shift towards hypothetico-deductive logic, in which theory is adjusted in light of individual facts. A new model of this kind should change our approach to drug research and development, and regulation. The assessment of new therapeutic agents would be viewed as a continuous process, and regulatory approval would no longer be regarded as the final step in the testing of a hypothesis, but rather, as the hypothesis-generating step. The main role of RCTs in this patient-centered research paradigm would be to generate hypotheses, while observations would serve primarily to test their validity for different types of patients. Under hypothetico-deductive logic, RCTs are considered "exploratory" and observations, "confirmatory".
  
  
  CONCLUSIONS
  In this era of tailored therapeutics, the answers to therapeutic questions cannot come exclusively from methods that rely on data aggregation, the analysis of similarities, controlled experiments, and a search for the best outcome for the average patient; they must also come from methods based on data disaggregation, analysis of subgroups and individuals, an integration of research and clinical practice, systematic observations, and a search for the best outcome for the individual patient. We must look not only to evidence-based medicine, but also to medicine-based evidence, in seeking the knowledge that we need.
authors.affiliation: Clinical Research Department, Lilly Spain Avenida de la Industria 30,28108 Alcobendas, Madrid, Spain. sacristan_jose@lilly.com
authors.forename: José A
authors.initials: JA
authors.lastname: Sacristán
mesh_terms: D002986:Clinical Trials as Topic / Q000379:methods*; D019091:Critical Pathways; D003657:Decision Making; D036262:Empirical Research; D019317:Evidence-Based Medicine; D006801:Humans; D008128:Logic; D018802:Patient-Centered Care / Q000639:trends*; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data