It is well known that antibiotics are overused. Even when the diagnosis of an infectious disease is correct, the choice or combination of antibiotics is commonly inappropriate.
Here is an interesting article on how diagnostic errors can impact the misuse of anti-infectives.
In the VA Health System, blinded reviewers judged the accuracy of the initial provider diagnosis for the condition that led to an antimicrobial course and whether the course was appropriate. The diagnoses were correct in 291 cases (58%), incorrect in 156 cases (31%), and of indeterminate accuracy in 22 cases (4%). In the remaining 31 cases (6%), the diagnosis was a sign or symptom rather than a syndrome or disease.
Here is where things become more interesting. Even with a correct diagnosis, 181/292 courses (62%) were appropriate, compared with only 10/208 (5%) when the diagnosis was incorrect or indeterminate or when providers were treating a sign or symptom rather than a syndrome or disease (P<.001).
This is an important point: to impact inappropriate antibiotics use, without a systematic approach to improving clinical-diagnostic reasoning, current efforts will fall short. This is a tall order and I am not optimistic.