It can take several hours or even days to get results of diagnostic tests that might provide key information about the potential cause of a patient’s infection. But in many cases, waiting that long to initiate treatment would be unwise or unpractical, so physicians often begin to do so based on an educated guess.
This practice has been linked to overtreatment and the emergence of antimicrobial resistance. For example, about half of patients with respiratory infections receive antibiotics, although many such infections are caused by viruses. This leads to unnecessary exposure to antibiotics that will not help the patient, may cause adverse events, and may contribute to the emergence of antibiotic-resistant bacteria.
Kuehn BM. IDSA: Better, Faster Diagnostics for Infectious Diseases Needed to Curb Overtreatment, Antibiotic Resistance . JAMA. 2013;310(22):2385–2386. doi:10.1001/jama.2013.283828