Use of urinary metabolic ratio to detect possible deception in patients prescribed buprenorphine

The data for 759,880 urine specimens, collected between January 2018 and September 2024, were quantitatively measured and considered for deception and poor metabolism using the metabolic ratio (MR) of norbuprenorphine to buprenorphine. We used this urinary MR of norbuprenorphine/buprenorphine to establish two decision limits, eg, a deception limit at log -1.9 (0.013), where deception is likely, and a warning limit at log -0.86 (0.138), where deception is less clear, and the MRs may result from either deception or extremely low metabolism. We showed that the use of MRs to set decision limits, instead of large, detected doses of the parent drug, better identifies deception in patients prescribed buprenorphine.