The Secure Anonymised Information Linkage databank Dementia e-cohort (SAIL-DeC)

Area of Science:

• Epidemiology
• Public Health
• Gerontology

Background:

• Dementia presents a growing global health challenge, necessitating robust research into its etiology, progression, and impact.
• The Secure Anonymised Information Linkage (SAIL) Databank offers a unique, large-scale repository of anonymized Welsh healthcare data, ideal for longitudinal dementia studies.

Purpose of the Study:

• To develop a reproducible, national dementia electronic cohort (SAIL-DeC) from the SAIL Databank.
• To maximize the utility of the SAIL-DeC for diverse dementia research questions and minimize research duplication.

Main Methods:

• Utilized linked primary care, hospital admission, mortality, and demographic data from the SAIL Databank (up to 2018).
• Applied algorithms using International Classification of Diseases (ICD-9/10) and Read (v2) codes to identify dementia cases and subtypes.
• Included participants born between 1900 and 1958 with available primary care data, creating derived variables for comorbidities and risk factors.

Main Results:

• The SAIL dementia e-cohort (SAIL-DeC) includes 1.2 million participants, contributing 18.8 million person-years of follow-up.
• 10% (129,650) of participants developed all-cause dementia, with Alzheimer's disease being the most common subtype (62%).
• Median observation time for dementia cases was 14 years.

Conclusions:

• A generalizable national dementia e-cohort has been successfully established.
• The SAIL-DeC is poised to significantly facilitate epidemiological dementia research.