Prevalence of dementia diagnoses in a safety net health system

Older adults from minoritized and socioeconomically disadvantaged backgrounds commonly receive health care in safety net health settings and may be at high risk of dementia. We assessed the prevalence of diagnosed dementia in a large safety net health system.

International Classification of Disease 10th Revision codes were used to classify presence of dementia for 147,689 older adults with at least one ambulatory encounter in 2019 using electronic health record data. Prevalence was calculated for the sample overall and by age cohort, sex, and race/ethnicity.

Diagnosed dementia prevalence was 0.3% for adults 50 to 64 and 3.0% for adults aged ≥ 65. Adults with diagnosed dementia were older, less likely to speak English, and had more medical comorbidities and higher health-care use than those without.

This study's estimates of dementia prevalence were considerably lower than other samples, which may be due to incomplete coding or to underdiagnosis of dementia in a safety net setting.

Six percent to 10% of older adults do not have Medicare and often receive health care in safety net health systems; however, little information exists about dementia care in this practice setting. The Los Angeles County Department of Health Services is the nation's second largest municipal health system and provides ambulatory care to > 30,000 older adults annually, of whom > 85% are from minoritized populations and 60% of whom do not have Medicare. We used International Classification of Disease 10th Revision codes and demographic and clinical information derived from the electronic health record to estimate age-adjusted prevalence of dementia in this safety net health setting. Prevalence of diagnosed dementia was significantly less than expected based on national samples, likely reflecting significant underdiagnosis and/or undercoding of dementia in this practice setting.