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

OBJECTIVE: Symptomatic knee osteoarthritis (SKOA) is a chronic, disabling condition, requiring long-term pain management; over 800,000 SKOA patients in the US use opioids on a prolonged basis. We aimed 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 US SKOA population. We included direct medical, lost productivity, criminal justice, and diversion costs. We modeled the SKOA cohort with a mean ± SD age of 54 ± 14 years and Western Ontario and McMaster Universities Osteoarthritis Index pain score of 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, respectively. 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 prolonged strong opioid use, the total lifetime opioid-related cost generated by the US SKOA population was estimated at $14.0 billion, of which only $7.45 billion (53%) were direct medical costs. CONCLUSION: Lost productivity, diversion, and criminal justice costs comprise approximately half of opioid-related costs generated by the US SKOA population. Reducing prolonged opioid use may lead to a meaningful reduction in societal costs that can be used for other public health causes.