The phrase "about the efficacy and" is correct and usable in written English.
It can be used when discussing the effectiveness of a particular method, treatment, or intervention, often in a research or analytical context.
Example: "The study focused on the debate about the efficacy and safety of the new drug."
Alternatives: "regarding the effectiveness and" or "concerning the efficiency and".
Defense attorneys have raised questions about the efficacy and purity of compounded drugs which lack federal approval.
But if Crack's reception in other cities is any indication, there is likely to be heated debate about the efficacy and the ethics of its offer.
Andrew is ambivalent about the efficacy (and the scientific validity) of psychotherapy, but he needs someone to talk to and he has no one else.
If the group's reception in other cities is any indication, there is likely to be heated debate in New York about the efficacy and the ethics of its offer.
But since then, the union has dug in, saying that WADA has failed to provide information it has requested about the efficacy and accuracy of the tests.
However, these efforts seem to contrast with a lack of knowledge about the efficacy and efficiency of these measures.
However, there is uncertainty about the efficacy and safety of blood-pressure-lowering treatments for many such patients.
There are only a few publications about the efficacy and tolerability of rituximab treatment in patients with autoimmune ocular inflammatory diseases.
Oral and written information about the efficacy and potential complications for each type of surgical intervention was given by the treating neurologist.
The availability of the various options comprises uncertainties about the efficacy and credibility of the standard schemes to the market participants.
This document describes laser in situ keratomileusis (LASIK) for myopia and astigmatism and examines the evidence to answer key questions about the efficacy and safety of the procedure.
