Results of randomized controlled trials (RCTs) and outcomes achieved in real-world clinical practice do substantielly differ. This fact is known as the "efficacy-effectiveness-gap", which describes differences between efficacy (i.e. does the intervention work under ideal circumstances?) and effectiveness (i.e. real-world benefit in every-day-life) results.
Explanations for this gap are various. Efficacious treatments in RCT may not readily be translated into clinical practice. Furthermore, variations between clinicians in terms of outcome assessment (e.g., symptoms, side effects) may differ. Increasingly seen in the cancer setting, medicines are commonly authorised solely based on phase 2 trial results or prematurely terminated phase 3 trials. Sound uncertainties are evident, as knowledge about and understanding of a new drug is still immature, study patients do not resemble real-life patients, and the choice of study outcomes (i.e. surrogates) are debatable and do not yield information about real-world effectiveness.
Different initiatives (e.g. GRADE, ESMO-MCBS) to bridge this gap and to better translate efficacy results into real-world benefit are being discussed. The monitoring of new medicines is now more important than ever, when it comes to safety and to the achievement of intended therapeutic outcomes.
After the session, the participant should be able to: • describe various reasons for differences between efficacy and effectiveness results of medicines; and, • provide examples of tools to be used in clinical practice to bridge this gap.
Educational need addressed
An in-depth understanding of the limitations of evidence generated in RCTs and opportunitites for translating evidence into everyday practice is key for hospital pharmacists when assessing and selecting medicines.