The phrase "overall efficacy" refers to the overall effectiveness or efficiency of something. It is a measure of how well or how successfully something can achieve its intended purpose or desired outcome. Full definition
The vaccine's overall efficacy against severe malaria in all age groups was around 31 %. (scientificamerican.com)
While the pros, cons, and overall efficacy of permissive parenting is still debated to this day, there's no doubting its one - time popularity. (motherhoodinpointoffact.com)
Lead author Professor Jack Cuzick from QMUL said: «We found that anastrozole and tamoxifen had similar overall efficacies, with slightly better outcomes for those who took anastrozole. (sciencedaily.com)