Question

Efficacy is defined as:

Group of answer choices

the degree to which a study may apply or be generalized to populations or groups who did not participate in the study

the extent to which a specific intervention produces a beneficial effect under ideal conditions

the degree to which a study is free from bias or systematic error

a measure of the extent to which an intervention, when deployed in the field under usual circumstances does what it is intended to do for a specified population

Answer 1

Efficacy is a measure of the extent to which an intervention, when deployed in the field under usual circumstances does what it is intended to do for a specified population.

This answer (last one) is correct.

Rest of the options are incorrect because first option says about efficacy in the group that has not particpated in study that seems to be illogical.

Second option is incorrect because efficay does not always mean a beneficial effect and defination is not specific it should be versatile enough to fir in egery circumstances.

Third option is incorrect because systemic errors and bias do affect efficacy but removal of bias is not efficacy.

Hope it helps. All the best ?