Real-world analysis of medication adherence and cost of care for comorbid conditions in patients with early Alzheimer's disease in the U.S.

AIM: To understand medication adherence and associated healthcare costs of patients with early Alzheimer's disease (AD).

METHODS

This retrospective cohort study used the Axon Registry® linked with claims data to examine medication adherence of U.S. patients with early AD (mild cognitive impairment [MCI] and mild dementia due to AD) from 2015 to 2022. Medication adherence was quantified by the proportion of days covered (PDC) over a one-year follow-up, and adherence rate was defined at a PDC ≥ 80%. Patient comorbidities and healthcare costs were described.

RESULTS

Of 333 patients included, 213 (64%) were female with a median (IQR) age 79 (72-83) years. Patients had a mean (SD) of 2.3 (2.1) comorbidities and took a mean (SD) of 3.0 (1.5) medications. Weighted-average PDC across medications was 74.4% with 7 out of 10 medication classes having a medication adherence rate lower than 60%. DPP-4 inhibitors had the highest medication adherence rate (66.67% of patients), and memantine had the lowest (39.13% of patients). Annual median (IQR) medical and pharmacy costs per-patient were $5,268 ($1,808-$14,651) and $658 ($187-$2,736), respectively.

CONCLUSION

Patients with early AD had multiple comorbidities and took multiple medications. Suboptimal medication adherence and high healthcare costs were observed.