'Nip it in the Bud!' Managing the Opioid Crisis : Supply Chain Response to Anomalous Buyer Behavior

Over the past three decades, the opioid epidemic has wreaked havoc upon thousands of communities across the US. In this study, we provide a supply-chain perspective to manage the ongoing opioid crisis. Using the ARCOS database -- which tracks opioid drug shipments across the entire supply chain in the US, spanning the period 2006 to 2012 -- we employ a novel anomaly detection algorithm – which we label a Density-Based Disjunctive Gamma / Beta (DDGB) algorithm -- to detect suspicious buyer activity. Our DDGB algorithm is non-intrusive on patient privacy because it does not rely on prescription-level data (from drug retailers or physicians). Using a random sample of 48,464 drug retailers and tagging 188 retail buyers, identified on the basis of observed convictions from the Drug Enforcement Administration (DEA) website, as “suspicious” buyers, we train our anomaly detection algorithm to detect suspicious buyers based on their historical opioid buying patterns. Our anomaly detection algorithm is built on a training set of 24,232 (unlabeled) drug retailers, while additionally relying on a validation set of 12,210 drug retailers (94 of whom are convicted buyers) in order to tune the algorithm’s threshold parameters. Our DDGB algorithm yields a precision of 100 % and a sensitivity of 46 % (thus yielding an F-1 score of 64 %) in terms of correctly detecting suspicious buyers in a test set of 12,210 drug retailers (94 of whom are convicted buyers). While we employ a total of 40 input variables, our anomaly detection algorithm ultimately relies upon only five input variables to achieve its impressive predictive accuracy. By applying our DDGB algorithm on real-time opioid shipment data as drug retailers around the country place orders, the DEA can flag those tagged as suspicious for further investigation. By halting large shipments of opioids through early identification of suspicious orders placed by either (willfully or otherwise) negligent or outright criminal drug retailers, dangerous drugs can be prevented from reaching vulnerable communities, thus saving lives