End-of-Life Care and Health Care Spending for Medicare Beneficiaries With Dementia in Accountable Care Organizations.

Importance: Individuals with dementia may receive high-intensity care at the end of life (EOL) that does not align with their preferences and is costly. Medicare Accountable Care Organizations (ACOs) are an alternative payment model that aims to incentivize high-quality care and lower spending.

Objective: To compare EOL care processes, outcomes, and health care spending between Medicare beneficiaries with dementia in a Medicare Shared Savings Program (MSSP) ACO and non-ACO.

Design, setting, and participants: This quasi-experimental study of EOL care used a nationally representative 20% random sample of Medicare fee-for-service beneficiaries with dementia (age ≥66 years) who died from 2017 to 2020. Difference-in-differences and event study design approaches were used to compare outcomes between beneficiaries attributed to MSSP ACO vs those who were not. Data were analyzed from June 2023 to December 2024.

Exposure: MSSP ACO entry from 2017 to 2019 vs non-ACO.

Main outcomes and measures: Differential changes in 5 areas: (1) billing for advance care planning; (2) palliative care counseling in last 6 months of life; (3) hospice in last 6 months of life; (4) high-intensity care in last 30 days of life (ie, emergency department visit, hospitalization, intensive care unit admission, in-hospital death, cardiopulmonary resuscitation or mechanical ventilation, feeding tube placement); and (5) health care spending in last 6 months of life.

Results: Of 162 034 eligible Medicare beneficiaries (mean [SD] age, 85.0 [7.9] years; 94 304 female [58.2%]), 51 191 (31.6%) were attributed to MSSP ACO. Adjusted trends in outcomes were similar between ACO and non-ACO groups before ACO entry. The difference-in-differences analyses found no evidence that EOL care processes or outcomes (eg, hospice in last 6 months of life, -0.4 percentage points [pp]; 95% CI, -1.4 pp to 0.5 pp; P > .99) or spending (eg, total health care spending in last 6 months of life, -$632; 95% CI, -$1377 to $113; P = .96) differed between beneficiaries treated in ACOs vs non-ACOs. The event study design also showed no evidence of differential changes in outcomes between the 2 groups. Sensitivity analyses using inverse probability weighting yielded similar results.

Conclusions and relevance: Using nationally representative data on beneficiaries with dementia at EOL, this quasi-experimental study found no evidence that EOL care processes, outcomes, or spending changed with ACO entry for Medicare fee-for-service beneficiaries vs non-ACO beneficiaries. Alternative payment models to ACOs may be needed to coordinate high-quality care with lower spending for beneficiaries with dementia at the EOL.