Postdoctoral researcher Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, United Kingdom
Background: A comprehensive picture of the use of main anti-dementia drugs over time is needed.
Objective: To describe the trend of anti-dementia drugs (ADD) prescribed in primary care in the UK and Spain.
Methods: Network-cohort study using data from the Information System for Research in Primary Care (SIDIAP) in Spain and the Clinical Practice Research Datalink (CPRD-Gold) in the UK, standardized to the OMOP common data model. We included subjects ≥40 years old, with ≥1 year of previous data and with ≥1 prescription of rivastigmine, galantamine, donepezil or memantine (index date) during the study period (SIDIAP: 01/01/2010-01/01/2020, CPRD: 01/01/2007-31/12/2019). Follow-up was from index date, the start of the study period or 1-year of valid data, until the end of enrolment or end of the study period. Statistics: We estimated yearly age-sex-incidence rates (IR, 95%CI) per 105 persons-year (PY). IR and Kaplan Meier curves were assessed for the duration and drug discontinuation.
Results: A total of 90,047 and 65,605 subjects with dementia were identified in SIDIAP and CPRD (65% were women in both countries), respectively. Of these, 17% (15,360) and 11% (7,481) were incident ADD users followed for 261,997.36 PY and 138,059.53 PY, respectively. An overall decreasing trend was observed in the incident use of ADD from 2013 in the UK and from 2014 in Spain. During the study period, the total incidence of ADD decreased a 34% in Spain (IR per 105 PY (95%CI) of 6,575 (6,192-6,977) in 2010 and 4,336 ( 4,069-4,617) in 2020, with two peaks in 2014 and 2018), and increased a 35% in the UK (IR per 105 PY (95%CI) of 3,215 (2,881-3,378) in 2007 and 4,908 (4,377-5,486) in 2019 with a peak in 2013). In Spain and the UK, ADD were more frequently prescribed to subjects of 65-79 years old (IR per 105 PY (95%CI) of 9,960 (9,706-10,220) and 7,361 (7,076-7,654) respectively) and to men (IR per 105 PY (95%CI) of 6,151 (5,989-6,318) and 6,285 (6,058- 6,518) respectively). In the UK high IR of incident ADD were observed in the younger population strata (40-64 years old) with IR that exceeded, in some years, those observed for the older subject (overall IR per 105 PY (95%CI) of 5,041 (4,418-5,727). Memantine was the most frequently ADD prescribed (IR per 105 PY (95%CI) of 4,042 (3,983-4,102) in SIDIAP, and IR of 2,558 (2,941-2,625) in the UK).
Conclusions: During the study period, only 17% in Spain and 11 % in the UK of persons with dementia initiated an ADD. A great variability is seen in the use of antidementia drugs in both countries, with an overall decreasing trend in the last decade in both countries. The higher incidence rates of ADD use among men contrasts with a higher proportion of women with dementia, and raises concerns regarding a possible gender inequity.
