INCIDENCE OF CHOLINERGIC AND MEMANTINE TREATMENT IN ALZHEIMER'S DISEASE IN FINLAND

Abstract

To the Editor: Cholinergic treatment has been available to patients with mild to moderate Alzheimer's disease (AD) for the last 10 years in Finland and memantine for moderate to severe AD for 5 years. Expenses of all four drugs (donepezil, galantamine, memantine, and rivastigmine; AD drugs) are reimbursed by application after diagnosis of AD and evaluation of the possibilities of pharmacological treatment. Eligibility for reimbursement of 42% must be applied for from the Social Insurance Institution of Finland (KELA) with a medical statement from a specialist in geriatrics or neurology. All granted reimbursement rights are collected in a nationwide register administered by KELA. The register data are labeled with a personal identification code. People living in long-term institutional care are excluded from the register. The local municipalities fully cover the costs of their care. In 2000, only 4,900 people were reimbursed for AD drugs in Finland, but in 2005, five times as many people (25,400) or 0.97% of people aged 40 and older were reimbursed. The rapid increase in the number of patients with AD eligible for reimbursement has raised several questions in public discussion. A register-based study was conducted to investigate the annual incidence rate of AD treated with cholinergic drugs or memantine. In Finland, the data for all granted reimbursement rights are organized in a national reimbursement register, which the National Social Insurance Institution manages. Every patient who has the right to reimbursement for medications for certain (chronic) diseases can be identified according to age, sex, and the disease the right was granted for. We examined the register and identified all persons aged 40 and older who were granted the reimbursement right for treatment of AD. Incidence rates were calculated per 1,000 person-years (py). The population at risk was calculated by excluding people living in institutions and those with ongoing AD drug treatment from the census of December 31, 2004. The age-specific numbers of people in institutions were collected from the national register of institutional care, administered by the National Research and Development Centre for Welfare and Health. The register covers all long- and short-term in-patient wards in Finland. Public (tax-funded) and private care providers are included in the care register. Incidence rates and 95% confidence intervals (CIs) were calculated using Poisson regression analysis. The number of new patients with AD with AD drug treatment in 2005 was 8,701. Women were more likely to receive AD drugs than men. The annual incidence rate of AD drug treatment was 4.1 per 1,000 py (95% CI=4.0–4.2) for women, 2.4 (95% CI=2.3–2.5) for men, and 2.8 (95% CI=2.7–2.9) for both sexes. The age-specific incidence rates are given in Table 1. Incidence rates increased with age. The incidence rates for people aged 90 and older were 27.0 (95% CI=24.5–29.8) for women and 26.1 (95% CI=18.8–27.1) for men. After adjusting for age and sex, the age- and sex-specific incidence rate of AD drug treatment in this study was comparable to that in Europe, published in a previous meta-analysis,1 up to the age of 85 in both sexes. After that age, the number of people living in an institution increases, and the validity of the reimbursement registers for describing the use of AD drugs in the population decreases. Of all new reimbursement rights, 78% (n=6,799) were granted to people aged 65 to 85 and 97% (n=8,467) to people aged 65 and older. If the age- and sex-adjusted incidence rates of the European Community Concerted Action on the Epidemiology and Prevention of Dementia (EURODEM) Group meta-analysis1 were projected to the Finnish population aged 65 and older, the annual number of new patients with AD in noninstitutional care would be approximately 7,430. Comparing the number of patients treated with AD drugs collected from the national reimbursement register and the number of patients with AD based on empirical studies by the EURODEM group,1 it can concluded that the majority of AD patients living outside of institutional care in Finland are already receiving symptomatic treatment with cholinergic drugs or memantine. Financial Disclosure: The Editor in Chief has determined that the authors have no conflict of interest related to this manuscript. Petteri Viramo has been a speaker for Pfizer/Eisai, Novartis, Lundbeck, and Janssen-Cilag. Author Contributions: Lauri Virta participated in study concept and design, acquisition of data, analysis and interpretation of data, and preparation of manuscript. Petteri Viramo participated analysis and interpretation of data, and preparation of manuscript. Sponsor's Role: No sponsor.