Societal Cost of Opioid Use in Symptomatic Knee Osteoarthritis Patients in the United States.

Background Symptomatic knee osteoarthritis (SKOA) is a chronic, disabling condition, requiring long-term pain management; over 800,000 SKOA patients in the USA use opioids chronically. We aim to characterize the societal economic burden of opioid use in this population. Methods We used the Osteoarthritis Policy Model, a validated computer simulation of SKOA, to estimate the opioid-related lifetime and annual cost generated by the USA SKOA population. We included direct medical, lost productivity, criminal justice, and diversion costs. We modeled the SKOA cohort with mean (SD) age 54 (14) years and Western Ontario and McMaster University pain score 29 (17) (0-100, 100-worst). We estimated annual costs of strong ($1,381) and weak ($671) opioid regimens using Medicare fee schedules, Red Book, the Federal Supply Schedule, and published literature. The annual lost productivity and criminal justice costs of opioid use disorder (OUD), obtained from published literature, were $11,387 and $4,264, per-person. The 2015-2016 Medicare Current Beneficiary Survey provided OUD prevalence. We conducted sensitivity analyses to examine the robustness of our estimates to uncertainty in input parameters. Results Assuming 5.1% prevalence of chronic strong opioid use, the total lifetime opioid-related cost generated by the USA SKOA population was estimated at $14.0 billion, of which only $7.45 billion (53%) were direct medical costs. Conclusions Lost productivity, diversion, and criminal justice costs comprise about half of opioid-related costs generated by the USA SKOA population. Reducing chronic opioid use may lead to a meaningful reduction in societal costs that can be used for other public health causes.