Estimating undiagnosed dementia in England using capture recapture techniques

Area of Science:

• Epidemiology
• Gerontology
• Public Health

Background:

• Capture-recapture techniques have not been widely applied to estimate dementia prevalence using routinely collected data in England.
• Estimating changes in undiagnosed dementia over time using electronic health records is crucial for public health planning.

Purpose of the Study:

• To estimate the number of undiagnosed dementia cases in England using routinely collected data.
• To assess changes in dementia diagnosis rates over time.
• To investigate disparities in dementia diagnosis based on age, ethnicity, socioeconomic deprivation, and sex.

Main Methods:

• Utilized linked primary care and hospital episode statistics from 1997 to 2018.
• Applied the Lincoln-Petersen estimator to estimate missing dementia diagnoses and total prevalence.
• Employed beta regression to analyze factors influencing dementia case identification.

Main Results:

• The proportion of identified dementia cases increased from 42.4% in 1997 to 84.4% in 2018.
• Estimated dementia prevalence in those aged ≥65 rose to 4.4% by 2018.
• Lower diagnosis rates were observed in the South Asian ethnic group and in younger age bands, while higher rates were seen in more deprived areas.

Conclusions:

• Dementia case identification has improved significantly, suggesting potentially lower underlying prevalence than previously estimated.
• Dementia remains under-diagnosed in younger individuals and among the South Asian population, necessitating targeted interventions.
• Further research is needed to replicate these findings and refine dementia prevalence estimates.