Prevalence and trend of central nervous system-active medication polypharmacy among US commercially insured adults with vs without early-onset dementia: a multi-year cross-sectional study.

Background: Limited data exist on the prevalence and trend of central nervous system (CNS)-active medication polypharmacy among adults with early-onset dementia (EOD) and whether these estimates differ for adults without EOD but with chronic pain, depression, or epilepsy, conditions managed by CNS-active medications.

Methods: A multi-year, cross-sectional study using 2012-2021 MarketScan Commercial Claims data was conducted among adults aged 30 to 64 years with EOD and those without EOD but having a diagnosis of chronic pain, depression, or epilepsy as comparison groups. For each disease cohort, the primary outcome was CNS-active medication polypharmacy defined as concurrent use of ≥ 3 CNS-active medications on the US Beers Criteria list that overlapped for > 30 consecutive days during 12 months following a randomly selected medical encounter with the disease diagnosis. A separate multivariate modified Poisson regression model was used to estimate time trends in CNS polypharmacy in each disease cohort. Differences in trend estimates between EOD and non-EOD disease cohorts were examined by an interaction between EOD status and yearly time.

Results: From 2013 to 2020, the annual crude prevalence of CNS polypharmacy was higher among adults with EOD (21.2%-25.0%) than adults with chronic pain (5.1%-5.9%), depression (14.8%-21.7%), or epilepsy (20.0%-22.3%). The adjusted annual prevalence of CNS polypharmacy among patients with EOD did not significantly change between 2013 and 2020 (adjusted prevalence rate ratio [aPRR], 0.94; 95% CI, 0.88-1.01), whereas a significant decreasing trend was observed among non-EOD cohorts with chronic pain (aPRR, 0.66; 95% CI, 0.63-0.69), depression (aPRR, 0.81; 95% CI, 0.77-0.85), and epilepsy (aPRR, 0.86; 95% CI, 0.83-0.89). The interaction analysis indicated that patients with epilepsy and depression (vs with EOD) had a decreasing probability of CNS-active medication polypharmacy over time (aPRR, 0.98 [95% CI, 0.98-0.99]; P < .001 for interaction for both conditions).

Conclusions: The prevalence of CNS polypharmacy among US commercially insured adults with EOD (vs without) was higher and remained unchanged from 2013 to 2021. Medication reviews of adults with EOD and CNS polypharmacy are needed to ensure that benefits outweigh risks associated with combined use of these treatments.