define efficacy vs effectiveness
Effectiveness. 1  Effectiveness is the extent to which planned outcomes, goals, or objectives are achieved as a result of an activity, strategy, intervention or initiative intended to achieve the desired effect, under ordinary circumstances (not controlled circumstances such as in laboratory).
Todayâs lesson was that, in medical parlance, âefficacyâ and âeffectivenessâ mean different things, and itâs a nuance thatâs quite significant. Efficacy is a narrower definition that means how well something works in an ideal or controlled setting, such as a clinical trial.