The 2 “Es” of Research: Efficacy and Effectiveness Trials

Studies that investigate the usefulness of various therapies fall along a continuum that ranges from those looking at whether an intervention can work under ideal circumstances (efficacy trials) to those that focus on whether a treatment works when applied in the real world (effectiveness trials). Whether a study is closer to one end of the spectrum or the other affects almost every aspect of the trial. These aspects include which patients are …