Incremental Healthcare Costs of Dementia and Cognitive Impairment in Community-Dwelling Older Adults: A Prospective Cohort Study

Background: Cognitive impairment and dementia are associated with higher healthcare costs; whether these increased costs are attributable to a greater comorbidity burden is unknown. We sought to determine associations of cognitive impairment and dementia with subsequent total and sector-specific healthcare costs after accounting for comorbidities and to compare costs by method of case ascertainment. Methods: Index examinations (2002-2011) of 4 prospective cohort studies linked with Medicare claims. 8 165 community-dwelling Medicare fee-for-service beneficiaries (4 318 women; 3 847 men). Cognitive impairment identified by self-or-proxy report of dementia and/or abnormal cognitive testing. Claims-based dementia and comorbidities derived from claims using Chronic Condition Warehouse algorithms. Annualized healthcare costs (2023 dollars) were ascertained for 36 months following index examinations. Results: 521 women (12.1%) and 418 men (10.9%) met the criteria for cognitive impairment; 388 women (9%) and 234 men (6.1%) met the criteria for claims-based dementia. After accounting for age, race, geographic region, and comorbidities, mean incremental costs of cognitive impairment versus no cognitive impairment in women (men) were $6 883 ($7 276) for total healthcare costs, $4 160 ($4 047) for inpatient costs, $1 206 ($1 587) for skilled nursing facility (SNF) costs, and $689 ($668) for home healthcare (HHC) costs. Mean adjusted incremental total and inpatient costs associated with claims-based dementia were smaller in magnitude and not statistically significant. Mean adjusted incremental costs of claims-based dementia versus no claims-based dementia in women (men) were $759 ($1 251) for SNF costs and $582 ($535) for HHC costs. Conclusions: Cognitive impairment is independently associated with substantial incremental total and sector-specific healthcare expenditures not fully captured by claims-based dementia or comorbidity burden.