|A term very much out of the literature on evaluation of drugs. The efficacy of an intervention refers to improvement in studies in laboratory style Randomised Controlled Trials, where diversity of clients can be limited and interventions tightly controlled. By contrast Effectiveness generally refers to studies carried out in routine clinical situations. Often used in a set of three terms: efficacy, effectiveness and finally efficiency which takes into account the costs involved in different interventions.|
The terms were popularised by a hugely influential monograph: Cochrane, A. L. (1972). Effectiveness and efficiency. Random reflections on health services. Nuffield Provincial Hospitals Trust. My own Zotero database note about the book, from 1999 says:
“The book that changed my life in so many ways I suppose!
entered years after the fact, must have read it in 1979 I think.”
I’d be more critical now but it was a tour de force.
Try also #
Randomised controlled trials (RCTs)
Practice Based Evidence (PBE)
In some ways our book is firmly based in the idea of practice based evidence which is largely about data from routine practice not from research but the distinctions between these three terms run right through the book.