title: Designing and analysing clinical trials in mental health: an evidence synthesis approach.
abstract: OBJECTIVE
  When planning a clinical study, evidence on the treatment effect is often available from previous studies. However, this evidence is mostly ignored for the analysis of the new study. This is unfortunate, since using it could lead to a smaller study without compromising power. We describe a design that addresses this issue.
  
  
  METHODS
  We use a Bayesian meta-analytic model to incorporate the available evidence in the analysis of the new study. The shrinkage estimate for the new study integrates the evidence from the other studies. At the planning phase of the study, it allows a statistically justified reduction of the sample size.
  
  
  RESULTS
  The design is illustrated using data from an Food and Drug Administration (FDA) review of lurasidone for the treatment of schizophrenia. Three studies inform the meta-analysis before the new study is conducted. Results from an additional phase III study, which were not available at the time of the FDA review, are then used for the actual analysis.
  
  
  CONCLUSIONS
  In the presence of reliable and relevant evidence, the design offers a way to conduct a smaller study without compromising power. It therefore fills a gap between the assessment of evidence and its actual use in the design and analysis of studies.
authors.affiliation: Novartis Pharma AG, Basel, Switzerland.
authors.forename: Simon
authors.initials: S
authors.lastname: Wandel
authors.affiliation: Novartis Pharmaceuticals, East Hanover, NJ, USA.
authors.forename: Satrajit
authors.initials: S
authors.lastname: Roychoudhury
mesh_terms: D014150:Antipsychotic Agents / Q000627:therapeutic use; D001499:Bayes Theorem; D002986:Clinical Trials as Topic / Q000706:statistics & numerical data*; D006801:Humans; D000069056:Lurasidone Hydrochloride / Q000627:therapeutic use; D008603:Mental Health / Q000706:statistics & numerical data*; D015201:Meta-Analysis as Topic; D012107:Research Design / Q000706:statistics & numerical data*; D018401:Sample Size; D012559:Schizophrenia / Q000188:drug therapy
chemical_list: D014150:Antipsychotic Agents; D000069056:Lurasidone Hydrochloride
keywords: MENTAL HEALTH; STATISTICS & RESEARCH METHODS