Steps to Close the Efficacy-Effectiveness Gap

A Health Affairs blog post looks at the differences between drug efficacy, as demonstrated in randomized clinical trials, and effectiveness, as seen in real-world evidence, and the steps that can be taken to close the gap between the two. The post notes that while in some situations the efficacy-effectiveness gap may be quite small, in other situations it is large. Addressing the gap depends in part, the authors say, on understanding the factors that generate and influence the size of the efficacy-effectiveness gap. Those factors include: 

•          characteristics of the treated disease;
•          patients’ clinical characteristics;
•          patients’ sociodemographic characteristics; and
•         methodological differences and treatment adherence.

Implications of the factors cited in the post include: 

•          the source of data used to carry out comparative effectiveness research can profoundly affect results;
•          users of comparative effectiveness research should extrapolate results of randomized trials to real-world populations conservatively and with the knowledge that trial results may not mirror outcomes among broad populations of patients treated in routine practice;
•          development and adoption of standardized, trusted methods for gathering real-world evidence across different patient populations, geographic regions, and health systems may help increase confidence in the accuracy of this data type and comparative effectiveness assessments that use it; and
•          reimbursement models that rely on estimates of comparative and absolute treatment value based on randomized clinical trials should account for uncertainty related to the efficacy-effectiveness gap.

The authors conclude that researchers, clinicians, and policymakers can take steps to close the efficacy-effectiveness gap, including: 

•         developing clinical trials with greater external validity through enrolling sicker patients in trials along with greater numbers of under-represented groups such as racial and ethnic minority patients, the elderly, and socioeconomically disadvantaged patients; and
•         taking a more holistic and comprehensive approach to addressing the root causes of non-adherence in real-world settings, which is a key driver of the efficacy-effectiveness gap.