Interruptions in Insurance Coverage and Prescription Drug Utilization: Evidence from Kentucky

This study examined how interruptions in insurance coverage affect purchases of prescription drugs for young adults. It used data spanning 2014 to 2018 from Kentucky's prescription drug monitoring program, which tracked the universe of federally-regulated (Schedule II-V) prescription drugs dispensed in the state. The study employed a regression discontinuity design based on the age limit at 26 for dependent insurance coverage for children. At age 26, the probability of purchasing a prescription decreased by 5%, with all subcategories of prescriptions affected. The share of generic prescriptions increased for stimulants (the only category observed with substantial branded prescriptions). By age 27, prescription purchases returned to levels observed at 25, but the share purchased with public insurance and the generic share for stimulants remained higher. The findings suggest that interruptions in insurance coverage decrease prescription drug utilization by young adults and that public insurance programs such as Medicaid are important for resuming treatment.