Estimated prevalence of dementia based on analysis of drug databases in the Region of Madrid (Spain).

INTRODUCTION: The progressive rise in dementia prevalence increases the need for rapid methods that complement population-based prevalence studies. OBJECTIVE: To estimate the prevalence of dementia in the population aged 65 and older based on use of cholinesterase inhibitors and memantine. METHODS: Descriptive study of use and prescription of cholinesterase inhibitors and/or memantine in 2011 according to 2 databases: Farm@drid (pharmacy billing records for the Region of Madrid) and BIFAP (database for pharmacoepidemiology research in primary care, with diagnosis and prescription records). We tested the comparability of drug use results from each database using the chi-square test and prevalence ratios. The prevalence of dementia in Madrid was estimated based on the dose per 100 inhabitants/day, adjusting the result for data obtained from BIFAP on combination treatment in the general population (0.37%) and the percentage of dementia patients undergoing treatment (41.13%). RESULTS: Cholinesterase inhibitors and memantine were taken by 2.08% and 0.72% of Madrid residents aged 65 and older was respectively. Both databases displayed similar results for use of these drugs. The estimated prevalence of dementia in individuals aged 65 and older is 5.91% (95% CI%, 5.85-5.95) (52 287 people), and it is higher in women (7.16%) than in men (4.00%). CONCLUSIONS: The estimated prevalence of dementia is similar to that found in population-based studies. Analysing consumption of specific dementia drugs can be a reliable and inexpensive means of updating prevalence data periodically and helping rationalise healthcare resources.

Consumption trends for specific drugs used to treat dementia in the region of Madrid (Spain) from 2002 to 2012.

INTRODUCTION: Analysing drug consumption in large population groups lets us observe consumption trends and compare them between different settings. OBJECTIVE: to analyse the time trends for consumption and costs of specific drugs used to treat dementia in the region of Madrid (Spain) and compare trends by sex and age cohort. METHODS: Descriptive study of cholinesterase inhibitors (N06DA) and memantine (N06DX01) dispensed in Madrid between 2002 and 2012 and covered by the Spain's national health system. Consumption was calculated by analysing changes in DDD (defined daily doses) to find total and yearly increases. The cost was estimated based on DDD price. To compare consumption rates by age and sex, we calculated DDD per 100 inhabitants/day. RESULTS: Between 2002 and 2012, consumption of drugs used to treat dementia increased sixfold. During this period, cholinesterase inhibitors accounted for 76.70% of the drugs consumed and memantine, 23.30%. The estimated cost rose by a by a factor of 5.7 over 11 years (or by a factor of 4 taking into account the use of generic drugs). In 2012, 2.42% of the patients aged 65 or over consumed cholinesterase inhibitors (women 2.82%, men 1.83%) and 0.90% consumed memantine (women 1.10%, men 0.61%). Consumption increased in age cohorts up to 86 to 90 (5.84% for cholinesterase inhibitors and 2.33% for memantine) and declined thereafter. CONCLUSIONS: Consumption of cholinesterase inhibitors and memantine gradually increased, but consumption in 2012 did not reach levels equivalent to dementia prevalence figures. Pharmaceutical expenditure restraint measures may temporarily slow the cost increase temporarily but if the same trend of consumption persists, costs will rise.