Hospitalization costs associated with 30-day unplanned readmissions and potentially preventable readmissions in US older patients with Alzheimer’s disease and related dementias

Background: Older patients with Alzheimer’s disease and related dementias (ADRD) face high rates of unplanned hospital readmissions, many of which may be avoidable through better care coordination and post-discharge support. This study aims to examine the costs associated with 30-day unplanned readmissions and potentially preventable readmissions (PPRs) among US older patients with ADRD. Methods: This study utilized the 2022 Nationwide Readmission Database to identify index admissions, 30-day unplanned readmissions, and PPRs in patients ≥ 65 years with ADRD, following the criteria established by the Centers for Medicare & Medicaid. Cost outcomes were assessed at the patient and event levels, including annual total hospitalization costs, 30-day unplanned readmission costs, and PPR costs. Results: Among older patients with ADRD (n = 743,855), 20.6% experienced at least one 30-day unplanned readmission. Patients with a 30-day unplanned readmission incurred significantly higher average total hospitalization costs per patient than those without ($67,566, [95% confidence interval (CI): $67,219–$67,914] vs. $27,239 [95% CI: $27,147 - $27,333], p < 0.001), translating to 117% higher adjusted total costs. Among readmitted patients, 50.6% experienced at least one PPR. Patients with a PPR incurred higher readmission costs than those without ($32,802 [95% CI: $32,490 - $33,113] vs. $24,525 [95% CI: $24,293 - $24,757], p < 0.001), translating to 25.9% higher adjusted readmission costs. Unplanned readmission costs represented 14.3% of total hospitalization costs, with PPR costs accounting for 75.7% of unplanned readmission costs. The highest PPR cost category was associated with infections ($780 million), followed by chronic conditions ($251 million). Conclusions: Unplanned readmissions and PPRs imposed a substantial financial burden on payers and healthcare systems caring for older patients with ADRD. Targeted efforts to improve care transitions and better manage infections and chronic conditions are critical for reducing PPRs and associated costs in this vulnerable population.