Efficacy can be defined as whether an intervention demonstrates a benefit over placebo or another intervention when tested in an ideal situation such as those created in a clinical trial. Effectiveness is different than efficacy in that a treatment or intervention works in real life in non-ideal situation or circumstance. Effectiveness cannot be measured in a clinical trial because the act of inclusion into a clinical trial is a distortion of usual real life practice. Efficiency in this context can be defined as doing things in the most economical way. For example, a drug may have shown efficacy in clinical trials and potentially effective, however, due to the price of the drug it will need to be made available to the public in the most efficient way for it to be beneficial