Usage Patterns of Anticoagulant Therapy in Patients with Mild Cognitive Impairment or Alzheimer’s Disease

Abstract Background This study aims to describe usage patterns and risk factors associated with anticoagulant therapy in patients with mild cognitive impairment (MCI) or Alzheimer’s disease (AD). Methods The United States Medicare claims database (2008– 18) was used to identify patients aged ≥65 years with MCI or AD and to evaluate their anticoagulant use from 2016– 17. A random sample of new anticoagulant users (n = 21,069) was selected. Baseline clinical characteristics during the 12 months prior to therapy initiation were constructed using Charlson Comorbidity Index components. Stable anticoagulant therapy was defined as continued use for ≥4 weeks. Using a nested case‐control design, a control group that did not receive anticoagulants was selected from the MCI/AD sample and matched to those receiving anticoagulants by year of therapy initiation, age, and sex. A mixed‐effects model evaluated the likelihood of stable anticoagulant use with census region as a random effect. Results Among 5,379,863 patients with MCI/AD, 487,745 were on anticoagulants (96% stable use). The mean age was 83.6 years (62% women, 86.4% White, 8.4% Black, 3.5% Hispanic, 1.1% Asian, and 1.6% Other/Unknown). The most frequently observed comorbidities were hypertension (86.7%), hyperlipidemia (70.5%), and mental disorder (45%) among those receiving anticoagulants, compared to 74%, 60%, and 44%, respectively, among matched controls. Use of anticoagulants was more likely to be observed in patients with MCI vs AD (odds ratio (OR) = 1.2, P <0.05), arrhythmia (OR = 3.41, P <0.05), congestive heart failure (OR = 2.04, P <0.05), depression (OR = 1.86, P <0.05), metastatic cancer (OR = 1.52, P <0.05), hypertension (OR = 1.31, P <0.05), cerebrovascular disease (OR = 1.31, P <0.05), composite indications for therapy such as coronary artery bypass graft/percutaneous coronary intervention, atrial fibrillation, etc. (OR = 1.29, P <0.05), and in women vs men (OR = 1.15, P <0.05), but less likely with renal disease (OR = 0.8, P <0.05). Anticoagulant use increased after 2012 ( P <0.05). Hispanic patients had the highest rate of anticoagulant use amongst all racial/ethnic groups (OR = 3.1 vs White [ P <0.05], OR = 1.1 vs Black [ P <0.05], OR = 1.9 vs Asian [ P <0.05]). Conclusions Patients with MCI were more likely to be stable anticoagulant therapy users than those with AD. Stable use of anticoagulant therapy was highest in Hispanic vs all other racial/ethnic groups, likely due to uncontrolled risk factors of the study.