….or surgery orders a Utox for AMS 1-2 days post-op and then consults the addiction service for suspected SUDs because it comes back positive for benzos, opioids, and fentanyl in a patient with no known Hx of or other reasonable suspicion for substance misuse….
The specificity for the cocaine assay is extremely high (mid to upper 90s%) and I can’t think of a reason for GC/MS if it comes back positive (other than in forensic cases), especially given the cost that has a fair likelihood of falling 100% on the patient. If positive, 99.9999% of the time the patient is either not telling the truth or used something with coke in it.