Health Care Utilization and Comorbidity History of North Carolina Medicaid Beneficiaries in a Controlled Substance "Lock-in" Program.

BACKGROUND Medicaid "lock-in" programs (MLIPs) are a widely used strategy for addressing potential misuse of prescription drugs among beneficiary populations. However, little is known about the health care needs and attributes of beneficiaries selected into these programs. Our goal was to understand the characteristics of those eligible, enrolled, and retained in a state MLIP.METHODS Demographics, comorbidities, and health care utilization were extracted from Medicaid claims from June 2009 through June 2013. Beneficiaries enrolled in North Carolina's MLIP were compared to those who were MLIP-eligible, but not enrolled. Among enrolled beneficiaries, those completing the 12-month MLIP were compared to those who exited prior to 12 months.RESULTS Compared to beneficiaries who were eligible for, but not enrolled in the MLIP (N = 11,983), enrolled beneficiaries (N = 5,424) were more likely to have: 1) substance use (23% versus 14%) and mental health disorders, 2) obtained controlled substances from multiple pharmacies, and 3) visited more emergency departments (mean: 8.3 versus 4.2 in the year prior to enrollment). One-third (N = 1,776) of those enrolled in the MLIP exited the program prior to completion.LIMITATIONS Accurate information on unique prescribers visited by beneficiaries was unavailable. Time enrolled in Medicaid differed for beneficiaries, which may have led to underestimation of covariate prevalence.CONCLUSIONS North Carolina's MLIP appears to be successful in identifying subpopulations that may benefit from provision and coordination of services, such as substance abuse and mental health services. However, there are challenges in retaining this population for the entire MLIP duration. ©2019 by the North Carolina Institute of Medicine and The Duke Endowment. All rights reserved.