ACE Unit Model Reduces Costs and 30-Day Readmissions

By 2030, 20% of the US population will be at least 65 years of age, creating an increased burden on the healthcare system. Delivering high-quality care while controlling costs includes strategies for improving patient outcomes, particularly in the elderly patient population.

Hospitalizations among the elderly are often associated with such adverse events as functional decline, delirium, undernutrition, and polypharmacy, leading to poor outcomes and higher costs. Acute Care for Elders (ACE) units have been developed over the past 20 years in hospitals nationwide. The ACE model utilizes an interdisciplinary team (IDT) to deliver hospital care, compared with a multidisciplinary model in which providers from all disciplines deliver care, but do so predominantly independently.

The primary goal of the ACE model is to reduce adverse events and outcomes in elderly patients using frequent IDT rounds that recognize and manage geriatric syndromes and initiate transition planning from the day of admission. Previous studies have shown that the ACE model improves processes of care as well as patient and provider satisfaction, and reduces rates of use of restraints and institutionalization.

To test the additional hypothesis that the ACE model at the University of Alabama at Birmingham (UAB) Hospital would reduce patient care costs for patients whose attending physicians were not geriatricians, researchers at UAB conducted a retrospective cohort study. The study was designed to compare variable direct costs from an interdisciplinary ACE unit with those from a multidisciplinary unit (usual care [UC]). Results of the study were reported in JAMA Internal Medicine [2013;173(11):981-987].

The study examined costs of care among hospitalists’ older patients who spent their hospital stay in either the ACE or UC unit in fiscal year 2010. The primary outcome measures were variable direct costs of ACE and UC patients. In addition, the researchers conducted a subset analysis restricted to the 25 most common diagnosis-related groups (DRGs) shared by ACE and UC patients. Cost ratios and 95% confidence intervals (CI) (adjusted for age, sex, comorbidity score, and case mix index [CMI]) were estimated using generalized linear regression.

Demographic characteristics and in-hospital mortality were similar between the 2 groups. The analysis including all DRGs demonstrated that the mean total variable direct cost per patient in the ACE group was $2109, compared with $2480 in the UC group.

When costs were stratified by CMI, cost ratios for ACE patients with low (0.82; 95% confidence interval [CI] 0.72-0.94) or moderate (0.74; 95% CI, 0.72-0.89) CMI scores were lowered significantly compared with UC patients. Care was cost neutral for patients with high CMI scores.

A significantly smaller proportion of patients in the ACE group were readmitted to the UAB hospital for any cause within 30 days (7.9% vs 12.8%; P=.02).

The subset analyses of the 25 most common DRGs found a significantly reduced mean variable direct cost per patient for the ACE group compared with the UC group: $1693 vs $2138; P<.001. Mean daily variable direct costs were also significantly less for the ACE unit ($484 vs $545; P<.001). The cost ratios for total and daily variable direct costs remained significant following adjustment (0.78 and 0.89, respectively).

“The ACE unit team model reduces costs and 30-day readmissions,” the researchers summarized. “In an era when improving care processes while reducing costs is a vital objective for the Medicare program and our nation as whole, the ACE model meets these goals,” they added.