BACKGROUND: Cognitive impairment and dementia are associated with higher healthcare costs
whether these increased costs are attributable to 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 four 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) ascertained for 36 months following index examinations. RESULTS: 521 women (12.1%) and 418 men (10.9%) met criteria for cognitive impairment
388 women (9%) and 234 men (6.1%) met 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 ,883 (,276) for total healthcare costs, ,160 (,047) for inpatient costs, ,206 (,587) for SNF costs, and 89 (68) for 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 59 (,251) for SNF costs and 82 (35) 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.