Patterns of dementia treatment in older adults with Parkinson’s disease using nationwide medical claims data

BACKGROUND: Dementia is a common feature in Parkinson’s disease (PD); however, data on dementia treatment patterns in patients with PD are scarce. This study aimed to evaluate the incidence of dementia in individuals with PD and to describe the dementia treatment patterns in the Korean elderly population. METHODS: We conducted a retrospective population-based cohort study using data obtained from the Korean National Health Insurance Service-Senior Cohort (NHIS-SC) database. The dataset comprised more than 500,000 health insurance beneficiaries from January 1, 2002 to December 31, 2015. We estimated the incidence of patients newly diagnosed with dementia during this observational period, compared patient demographics, and analyzed the exposure to anticholinergic drugs among PD patients with (PD + D) and without (PD-D) dementia. Furthermore, the duration to dementia diagnosis and patterns of dementia treatment were evaluated. RESULTS: A cohort of 28,537 patients aged 60 years or older who were diagnosed with PD by the NHIS was established. Within this cohort, 8620 patients were eligible study participants according to strict inclusion/exclusion criteria. Of these individuals, 3879 (45.0%) patients were newly diagnosed with dementia; the incidence of dementia in PD was 15.2 per 1000 person-years. The proportion of women was higher in the PD + D (64.6%) than the PD-D group (58.2%) (P < 0.001); furthermore, the use of anticholinergic medication was greater in PD + D (37.6%) than in PD-D (24.0%) patients. The incidence curves for dementia over time were the steepest during the first year and decreased every year thereafter. Approximately 60% of PD patients were diagnosed with dementia during the first 3 years. Regarding the use of anti-dementia drugs, 2539 (65.5%) of 3879 PD + D were prescribed medication. During the observation period, 1799 (70.9%) patients were prescribed only one type of anti-dementia drug. In this monotherapy group, the most commonly prescribed medication was donepezil (1313[73.0%]), followed by rivastigmine (capsule and patch; 246[13.7%]), memantine (187[10.4%]), and galantamine (53[2.9%]). CONCLUSIONS: In Korea, dementia was observed to occur relatively soon after the diagnosis of PD. Anti-dementia medication was prescribed to approximately 66% of PD + D patients, with the majority receiving donepezil as monotherapy. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12877-022-03028-0.