title: How and why criteria defining moderators and mediators differ between the Baron & Kenny and MacArthur approaches.
abstract: OBJECTIVE
  In recognition of the increasingly important role of moderators and mediators in clinical research, clear definitions are sought of the two terms to avoid inconsistent, ambiguous, and possibly misleading results across clinical research studies.
  
  
  METHODS
  The criteria used to define moderators and mediators proposed by the Baron & Kenny approach, which have been long used in social/behavioral research, are directly compared to the criteria proposed by the recent MacArthur approach, which modified the Baron & Kenny criteria.
  
  
  RESULTS
  After clarifying the differences in criteria between approaches, the rationale for the modifications is clarified and the implications for the design and interpretation of future studies considered.
  
  
  CONCLUSIONS
  Researchers may find modifications introduced in the MacArthur approach more appropriate to their research objectives, particularly if their research might have a direct influence on decision making.
authors: Department of Psychiatry and Behavioral Sciences, Stanford University, CA, USA. hckhome@pacbell.net
authors: Helena Chmura
authors: HC
authors: Kraemer
authors: Michaela
authors: M
authors: Kiernan
authors: Marilyn
authors: M
authors: Essex
authors: David J
authors: DJ
authors: Kupfer
mesh_terms: D001524:Behavioral Medicine / Q000706:statistics & numerical data*; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D009626:Terminology as Topic