Continuous nonprescribed use of heroin, morphine,  oxycodone, hydrocodone, codeine, meperidine, tramadol, carfentanil or fentanyl over a 6 month or longer period is indicative of Opioid Use Disorder. It can be evidenced by :

IV skin tracks

Skin popping scars from prior or current abscesses

Prior detox/maintenance treatment records

ER/hospital discharge records for opioid drug overdose

Drug Screen Tests using Urine, Saliva, Blood, Sweat, Hair, or Interstitial Fluid. (methods to sense analytes include lateral flow/dip sticks, electrochemistry, or others)

Opiate withdrawal symptoms and signs -COWS assessment

CURES report indicating if there are any prescribed controlled substances – compared to drug screen results.

Biomarkers of opiate dependency. – EEG, Metabolic profile, fMRI, and others

Legal records of opiate use

Continuous opiate level monitoring