Price elasticity of demand for buprenorphine/naloxone prescriptions

Abstract

Although there have been supply-side efforts in response to the opioid crisis (e.g., prescription drug monitoring programs), little information exists on demand-side approaches related to patient cost sharing that may affect utilization of and adherence to pharmacotherapy by individuals with opioid use disorder. Among individuals who had initiated pharmacotherapy, we estimated the price elasticity of demand of prescription fills of buprenorphine/naloxone, a common pharmacotherapy drug, overall and by patient characteristics. Using the IBM MarketScan® Commercial Claims and Encounters Database for individuals with employer-sponsored private health insurance coverage, we examined the relationship between cost sharing and the number of buprenorphine/naloxone prescription fills using enrollee-level longitudinal fixed effects models. Cost sharing was expressed as a price index for each employer-plan. By including enrollee-level fixed effects, the identification of the effect of interest comes from longitudinal variation in prices across multiple time points for each enrollee. Overall, the demand for buprenorphine/naloxone was price inelastic (p = 0.191). However, some subgroups were responsive to price. A doubling of price was associated with a decrease in fills by 3.0% for enrollees aged 45–64 years (p = 0.029); 5.7% for those in rural areas (p = 0.033); 5.8% for residents of the South (p ≤0.001); and 3.0% for those enrolled in an HMO (p = 0.004). Insurers should consider the effects on these groups before increasing beneficiary out-of-pocket costs for pharmacotherapy and efforts to increase adherence should consider that price may be a barrier for some subgroups with OUD.