Pharmaceutical consumption and cost in patients with dementia: A longitudinal study by the Registry of Dementias of Girona (ReDeGi) in Catalonia (Spain)

Abstract

Objective: Drug spending increases exponentially from the age of 65-70 years, and dementia is one of the diseases significantly contributing to this increase. Our aim was to describe pharmaceutical consumption and cost in patients with dementia, using the Anatomical Therapeutic Chemical (ATC) classification system. We also assessed the evolution of costs and consumption, and the variables associated to this evolution during three years.

Methods: Three years prospective cohort study using data from the ReDeGi and the Health Region of Girona (HRG) Pharmacy Unit database from the Public Catalan Healthcare Service (PCHS). Frequency of consumption and costs of ATC categories of drugs were calculated.

Results: Sample of 869 patients with dementia, most of them with a diagnosis of degenerative dementia (72.6%), and in a mild stage of the disease (68.2%). Central nervous system (CNS) drugs had the highest consumption rate (97.2%), followed by metabolic system drugs (80.1%), and cardiovascular system drugs (75.4%). Total pharmaceutical cost was of 2124.8 € per patient/year (standard deviation (SD)=1018.5 €), and spending on CNS drugs was 55.5% of the total cost. After 36 months, pharmaceutical cost increased in 694.9 € (SD=1741.9), which was associated with dementia severity and institutionalization at baseline.

Conclusions: Pharmaceutical consumption and costs are high in patients with dementia, and they increase with time, showing an association with baseline dementia severity and institutionalization. CNS drugs are the pharmaceuticals with highest prescription rates and associated costs.

Keywords: Cost; Dementia; Drug consumption; Longitudinal; Registry.