Central Nervous System-Active Prescriptions in Older Veterans: Trends in Prevalence, Prescribers, and High-risk Populations

BACKGROUND: Little is known about the prevalence or chronicity of prescriptions of central nervous system-active (CNS-active) medications in older Veterans. OBJECTIVE: We sought to describe (1) the prevalence and trends in prescription of CNS-active medications in older Veterans over time; (2) variation in prescriptions across high-risk groups; and (3) where the prescription originated (VA or Medicare Part D). DESIGN: Retrospective cohort study from 2015 to 2019. PARTICIPANTS: Veterans age >= 65 enrolled in the Medicare and the VA residing in Veterans Integrated Service Network 4 (incorporating Pennsylvania and parts of surrounding states). MAIN MEASURES: Drug classes included antipsychotics, gabapentinoids, muscle relaxants, opioids, sedative-hypnotics, and anticholinergics. We described prescribing patterns overall and in three subgroups: Veterans with a diagnosis of dementia, Veterans with high predicted utilization, and frail Veterans. We calculated both prevalence (any fill) and percent of days covered (chronicity) for each drug class, and CNS-active polypharmacy (>= 2 CNS-active medications) rates in each year in these groups. KEY RESULTS: The sample included 460,142 Veterans and 1,862,544 person-years. While opioid and sedative-hypnotic prevalence decreased, gabapentinoids exhibited the largest increase in both prevalence and percent of days covered. Each subgroup exhibited different patterns of prescribing, but all had double the rates of CNS-active polypharmacy compared to the overall study population. Opioid and sedative-hypnotic prevalence was higher in Medicare Part D prescriptions, but the percent of days covered of nearly all drug classes was higher in VA prescriptions. CONCLUSIONS: The concurrent increase of gabapentinoid prescribing paralleling a decrease in opioid and sedative-hypnotics is a new phenomenon that merits further evaluation of patient safety outcomes. In addition, we found substantial potential opportunities for deprescribing CNS-active medications in high-risk groups. Finally, the increased chronicity of VA prescriptions versus Medicare Part D is novel and should be further evaluated in terms of its mechanism and impact on Medicare-VA dual users.