Fig. 3

Graphical representation of interrupted time series analysis (ITSA)^a of the proportion quarterly opioid-involved overdose deaths involving prescription and illicit opioids^b

^a Upper and lower sub-figures represent ITSA of prescription and illicit opioid-involved overdose rates, respectively, while each column represents a unique ITSA intervention. Red lines represent estimated intervention impacts while dotted red lines represent estimated counterfactual (i.e., no intervention) trends. Blue dotted lines represent intervention start dates while grey shaded areas represent a six-month (two-quarter) transition period after which the intervention impact is theorized to have begun; a three-month (one-quarter) lag/transition period, which was modeled and tested separately, is not shown

^b Prescription opioid overdoses were defined as those associated with oxycodone or hydrocodone, while illicit opioid overdoses were defined as those involving heroin and synthetic opioids other than methadone, including fentanyl, fentanyl analogues, 4-anpp, and u-47700. Data are from the West Virginia Forensic Drug Database, which compiles data from the West Virginia Office of the Chief Medical Examiner