Additional hospitalization costs associated with delirium among older adults: evidence from the Medicare Current Beneficiary Survey

TL;DR

Delirium during hospitalization increases healthcare costs for older adults, with additional expenses averaging thousands of dollars per case.

Contribution

This study provides nationally representative estimates of hospitalization costs associated with delirium using Medicare data.

Findings

Delirium was linked to $8,110 higher hospital charges and $1,631 higher Medicare payments per hospitalization.

Delirium-related costs were higher among patients with Alzheimer's disease and related dementias (ADRD).

Abstract

Delirium, an acute state of confusion and inattention, affects over 7 million hospitalized adults in the United States (US) annually. Health care costs associated with delirium in the US have been estimated from prospective observational cohorts of hospitalized older adults, but these estimates may be skewed based on the community examined. Therefore, there is a need for estimates from nationally representative data.

Additional expenditures associated with experiencing delirium during hospitalization were estimated after analyzing all inpatient claims from the 2019–2021 Medicare Current Beneficiary Survey (MCBS) research claim files. Hospital expenditure was calculated as the total charges for all services included in the institutional claim and total Medicare payments. Delirium during hospitalization was ascertained based on ICD-9 and ICD-10 codes from hospital claims data. We estimated the excess cost associated with delirium using a mixed-effects linear model with a random intercept at the individual level adjusting for demographic and health characteristics of patients.

In a sample of 2,599 Medicare beneficiaries (mean age 78.4 years, 52.9% female, 81.8% White), we identified a total of 5,677 hospitalization claims. A total of 286 (11.0%) participants experienced at least one delirium episode. In fully adjusted models, delirium was associated with $8,110 (95% confidence interval, CI: $1,860, $14,360) additional hospital charges and $1,631(95% CI: $527, $2,735) additional Medicare payments, compared to hospitalization without delirium. Delirium was more costly among participants with ADRD than those with no history of ADRD.

Findings from this nationally representative dataset show that delirium during hospitalization is associated with higher health care costs. As delirium is considered a modifiable risk factor for dementia, another condition with significant associated healthcare costs, these expenses may be preventable. Additional research is needed to understand the economic impact of delirium prevention and intervention.

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