A narrative review completed by GetReal examined the literature related to the concept of the efficacy-effectiveness gap (Nordon et al., 2016). The authors used inductive analysis to identify the different ways, here called ‘paradigms’ used to understand the efficacy-effectiveness gap (see Clarify the Issues) that have evolved over the last few decades. These are summarised in the table below.
Paradigm | Description |
1. Method used to assess the effects of a medicine |
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2. Impact of patient and clinician’s behaviour or real-life characteristics of the healthcare system |
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3. Interaction between a medicine’s biological effect and contextual factors |
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Current view on the efficacy-effectiveness gap
The third and current paradigm provides the opportunity to look beyond the differences between ‘standardised’ and ‘real-life’ characteristics of the healthcare system and study designs. Many experts consider there to be a continuum between explanatory and pragmatic trials, rather than a simple dichotomy: explanatory vs pragmatic: ‘the explanatory‑pragmatic continuum’. Future research will determine if the identification of these contextual factors can help to design RCTs that provide better estimates of medicines’ effectiveness.
Key contributor
Clementine Nordon, LASER