1. Introduction to the Acute Care for Elders (ACE) Program
The Acute Care for Elders (ACE) program represents a specialized model of healthcare meticulously crafted to mitigate the risk of functional decline in older adults during hospitalization for acute medical conditions. Hospitalization, while necessary, can inadvertently lead to a decrease in independence for elderly patients, often termed hospital-associated disability. The ACE program is specifically designed as a continuous quality improvement strategy to maintain and, where possible, restore the self-care abilities of elderly patients from the moment of hospital admission through to discharge. The core objective is to prevent loss of independence in activities of daily living (ADLs) and to rehabilitate any ADL independence diminished during their hospital stay.
The ACE intervention is built upon the principles of continuous quality improvement and comprehensive geriatric assessment, aiming to create a superior system of care for acutely ill older adults. This multifaceted approach incorporates four essential elements: a carefully designed physical environment to bolster patient independence and safety, patient-centered care delivered directly at the bedside by registered nurses in collaboration with an interdisciplinary team of healthcare providers, thorough discharge planning initiated early in the hospitalization and informed by the interdisciplinary team’s insights, and rigorous medical care review to ensure optimal medication management and clinical care.
Recognizing the inherent risks of iatrogenic illness, the adverse effects of immobility and prolonged bed rest, and the general “hazards of hospitalization,” the ACE model directly addresses these concerns. Studies have consistently demonstrated that a significant number of older adults experience a loss of independence in physical functioning between hospital admission and discharge, underscoring the detrimental impacts of hospitalization on this vulnerable population. However, research has also shown that modifying the hospital environment and employing interdisciplinary teams can significantly improve patient outcomes. The ACE model emphasizes creating an environment that safely supports the personal needs and abilities of older patients. An interdisciplinary team, proficient in assessing and enhancing the physical functioning of acutely ill older adults, facilitates a patient-centered approach. With support from the John A. Hartford Foundation, researchers were able to develop, implement, and evaluate the ACE unit, measuring its effectiveness on basic ADL outcomes. Secondary outcomes assessed included healthcare costs, hospital stay duration, self-reported mobility, and transitions to nursing facilities or home. Importantly, the ACE intervention was designed to be cost-neutral. Three randomized clinical trials have evaluated the ACE unit, each with slightly different objectives but all adhering to the core principles and adapting pragmatically as part of a continuous quality improvement process. These trials compared standard care on medical–surgical units with the specialized care provided within the ACE unit.
This article aims to elucidate the ACE model and the rationale behind its effectiveness. We will explore the conceptual underpinnings of the ACE intervention, the evidence from clinical trials supporting its superiority over traditional care, lessons learned from these experiences—including challenges to wider adoption—and future directions for acute care models for the elderly. These insights are increasingly relevant as the population ages, with older adults facing higher hospitalization rates, longer hospital stays, and complex chronic conditions. The rising costs of hospitalization for Medicare patients further underscore the need for effective and efficient models like ACE.
2. Conceptual Foundations of Hospital-Associated Disability and the ACE Response
Acute illness is a significant stressor for older adults and their families. Elderly patients often enter hospitals already managing multiple chronic conditions. Factors inherent to the hospital environment, such as an unfamiliar and potentially unsafe physical setting and routine care processes (e.g., restricted mobility), can inadvertently contribute to a loss of functional independence or impede the restoration of pre-illness physical functioning. The concept of “hospital-associated disability” highlights this phenomenon, explaining how older patients, with their diminished physiological reserves and pre-existing conditions, are particularly susceptible to functional decline during hospitalization. Age-related declines in muscle mass, strength, and aerobic capacity can be further exacerbated by the deconditioning effects of immobility, postural instability, and impaired reflexes that can lead to orthostatic hypotension and unsteadiness. Emerging physical impairments can also affect cognitive function, potentially leading to delirium, anxiety, or depressive symptoms.
Traditional, fragmented healthcare delivery, often isolates patients and families, hindering their active involvement in recovery and return to independent living. Hospital-associated conditions like falls, delirium, pressure ulcers, and catheter-associated infections are common in patients over 65 yet are often preventable. A combination of a non-optimal hospital environment, prolonged bed rest, inadequate nutrition, immobility, and depersonalization can significantly increase the risk of functional decline, leading to patient disability. However, interventions aimed at disrupting this cycle of decline have the potential to improve hospital outcomes significantly. Enabling patients to maintain mobility, engage in self-care, socialize, sleep adequately, and maintain good nutrition are crucial aspects of mitigating the adverse effects of hospitalization. Immobility, in particular, has devastating consequences on functional status, directly impacting the ability to perform basic ADLs like transferring and walking. The ACE Unit was conceived to systematically counteract hospital-associated disability, enhance patient flow efficiency, and prioritize patient-centeredness.
3. Development and Key Components of the ACE Unit
Implementing an ACE unit represents a significant shift in the culture of hospital care for older adults. It necessitates a move from a disease-centric approach to one that prioritizes the patient as a whole. Full implementation involves adapting the physical environment to foster patient independence and safety, and transitioning from multidisciplinary to truly interdisciplinary team-based care. This transformation requires a strategic business approach that emphasizes the value proposition to hospital leadership, demonstrating a return on investment and enhanced institutional reputation. While a phased approach can guide the development of ACE unit components and business strategy, securing buy-in from hospital administration is crucial, as the costs of unit renovation and staff retraining can be substantial. Although research indicates that ACE units do not escalate hospitalization costs, initial investments in staff training and facility upgrades may be necessary, especially in older hospitals. The first ACE unit at University Hospitals of Cleveland, for example, was established in an older medical–surgical unit with 15 beds dedicated to geriatric patients. Modernization was essential, and external funding facilitated significant physical restructuring to create the prepared environment. Today, many of these structural design elements are standard in newly built or upgraded hospitals.
Once hospital leadership commits to establishing an ACE unit, an advisory council composed of leaders from relevant departments is formed to guide program development and foster interdisciplinary collaboration. In the original ACE unit, each director contributed to developing patient care guidelines for complex older adults. This council also promotes collaboration and advocates for high-quality geriatric care. The advisory council meets regularly to assess the ACE unit’s progress and review performance metrics, including hospital costs, quality indicators, and the prevention of hospital-acquired conditions, demonstrating the return on investment. This collaborative model fosters shared ownership of the ACE unit among healthcare providers, ensuring program sustainability and growth.
3.1. The Prepared Environment: Designing for Independence and Safety
The design of the first ACE unit was informed by principles of architectural design for acute and long-term care, inpatient rehabilitation, and the practical experience of clinicians and researchers. To create a more homelike environment and minimize risks of falls, confusion, anxiety, and deconditioning, the original unit incorporated several key features. These included carpeting, handrails in hallways, uncluttered corridors, and earth-tone wallpaper and paint with contrasting floor, wall, and ceiling colors to aid depth perception. Diffuse lighting, including wall sconces and lighting behind patient beds, was installed, along with lever door handles, large clocks and calendars for orientation, elevated toilet seats in bathrooms, and sound-absorbing wall hangings and carpeting to reduce noise levels. A dedicated social space was created to encourage patient and family interaction. While innovative in the 1990s, many of these elements, except for carpeting (compressible synthetic flooring is now preferred), are common in modern hospitals. The current emphasis on wellness, calming environments, privacy, and noise reduction in hospital design reflects market demands, aiming to improve patient satisfaction and safety. As hospital designs become more “senior-friendly,” they increasingly align with the ACE prepared environment, potentially reducing the need for extensive renovations of existing medical-surgical units. Furthermore, hospitals must comply with the Americans with Disabilities Act (ADA), with room specifications that are highly compatible with the ACE prepared environment. The prepared environment concept aligns with a safety culture focused on preventing hospital-acquired conditions, immobility, acute confusion, and geriatric syndromes. Integrating ACE unit design principles into standard hospital construction and upgrades is a logical step towards improving patient care.
Table 1. Prepared and Safe Hospital Environment.
| Goal: Standardize safe furniture and equipment placement in the patient room and public thoroughfares to prevent falls and injuries and to optimize patient self-care. |
|---|
| GENERAL PRINCIPLES FOR PATIENT ROOM: |
| Note: Americans with Disabilities Act (ADA) requires 10% of Acute Care beds comply with ADA standards |
| – ❖CONTENTS per Patient Bed – ○One patient chair (with armrests) – ○One visitor chair (armrests preferred). If additional visitor chairs, consider using folding chairs in order to remove or fold away when not in use. |
| Note: If only one chair can fit into the room, the priority is the patient chair. |
| Also, recommendation is that 20% of acute care beds to be equipped with bariatric furniture. |
| – ○One night stand – ○One over-bed table – ○Telephone (type that mounts onto side rail preferred) – ○Patient waste can – ○Two staff waste cans (regular trash and hazardous waste) – ○No linen carts (holder on wall with linen bags preferred) – ○These items are needed only if patient is using them – ▪IV pole – ▪Bedside commode with toilet paper holder mounted on side – ○Electrical outlets every 12 feet (standard) can be adapted to equipment and usage needs in the patient room – ○Furniture and sinks with rounded edges (minimizes injury if patient falls) |
| – ❖SPACING/PATHWAYS – ○Clearance space of 3 feet exists around the bed, except at the headwall (ADA). Primarily applies to stationary furniture/equipment. Movable furniture is permitted within this space. – ○Minimum 3 feet between patient beds in semi-private rooms (ADA) – ○Vertically, anything protruding from the wall, within a zone of 80 inches from the floor, must be 2. ○Clear pathway from patient bed to bathroom and entrance/exit to room |
| – ❖SAFE BED EXIT – ○Safe bed exit side is identified and located on patient’s side of preference, or dominance, especially if a functionally limiting clinical condition exists (such as weakness due to stroke). If no patient preference, the default for safe exit is the side of the bed closest to the bathroom. – ○Safe exit side of bed is visually noted in the patient’s room – ○Items on safe exit side include: – ▪Night stand (within reach) |
| – ❖IV Pole (if being used by patient) – ○Bedside commode (if being used by patient) – ○Items NOT on safe exit side include: – ▪Over bed table – ▪Chairs (patient and visitor) – ▪Patient’s garbage can |
| – ❖GRAB BARS – ○Continuous grab bars or handrails available along walls, except where there is affixed, stationary furniture. |
| Note: This decreases room space by 3 inches on every side there is a grab bar. May want to consider furniture placement as an alternative. |
| – ❖FURNITURE/EQUIPMENT – ○Patient chair is designated as such and has armrests – ○Rounded corners on furniture or bumper guards on edges – ○Assistive equipment and call bell is within patient’s reach – ○Lever handles on doors, no doorknobs (ADA) – ○Divider curtains between beds pull all the way back to the wall – ○Electrical cords bundled and kept away from walking paths |
| – ❖LIGHTING – ○Diffuse lighting that projects vertically – ▪Perforated screen covers to minimize glare if patient passes underneath on a carrier – Under bed light that illuminates floor around the bed – ○Low lighting along base of walls in patient room, especially to light path to bathroom and entrance/exit of patient room – ○Light controls on bed rail and on call light controller |
| – ❖BATHROOM – ○No tub – ○Walk-in/wheel-in shower (ADA) – ○Doorway wide enough for patient and equipment (Standard dimensions: patient room an entry door width of 48 inches, bathroom entry width of 36 inches) – ○Continuous grab bars, especially behind and on wall side of toilet (ADA) – ○Flip down bars not recommended for toilet area, instead use wall mounted or toilet mounted grab bar that utilizes a mounting bracket – ○Sinks with no support between sink and floor must meet mounting standards to tolerate patient weight leaning on sink – ○“No Slip“ surface on floor (0.08 slip co-efficient on potentially wet surfaces) – ○Devices available to elevate toilet seat 17–19 inches from floor (ADA) – ○Emergency cord accessible from both toilet and shower (ADA) – ○Curbless shower threshold (ADA) with two drains (one inside shower and one outside shower area) – ○Sensor light in bathroom that automatically turns on when someone enters – ○Glow in the dark toilet seats, or seats with a glowing border to help patient locate it (not necessary if lighting turns on automatically on entry). Nightlight that illuminates toilet area is an alternative. |
| – ❖HALLWAYS 8 foot wide corridors – ○No equipment permanently stored in hallways – ○When in use, equipment placed on one designated side of hall – ○Low glare floors with visual breaks (synthetic surfaces) – ○Handrails on both sides of the hall that are either a different color than the walls, or have built in lighting to provide contrast against the wall – ○Diffuse lighting that projects vertically – ○Mirrors for blind corners – ○“High risk” patient room with adjustable visibility to front of room for monitoring |
3.2. Patient-Centered Care and the Interdisciplinary Team
Patient-centered care is fundamentally about providing respectful and responsive care that aligns with each patient’s unique preferences, needs, and values, ensuring these values guide all clinical decisions. This approach acknowledges patients’ cultural backgrounds, personal preferences, family needs, and values, integrating them as active members of the interdisciplinary team. In ACE units, healthcare providers who are deeply committed to elderly care share responsibility with the attending physician for patient management and team interactions. The interdisciplinary team model fosters coordinated care and open communication among team members, as well as direct engagement with patients and families. Unlike traditional siloed or multidisciplinary approaches, ACE teams prioritize required professional services, leading to greater efficiencies in care delivery. Recommendations are based on established best practices for ACE unit patients.
Nurses play a crucial role in the ACE unit model, providing continuous 24/7 bedside care. Advanced practice nurses typically lead interdisciplinary rounds and maintain daily communication with attending physicians and consultant geriatricians. Many ACE units employ trained geriatric resource nurses and are affiliated with Nurses Improving Care of Healthcare Systems for Elders (NICHE). Under the supervision of advanced practice nurses and with guidance from geriatric resource nurses, primary bedside nurses are trained in protocols for the bedside care of older adults. These protocols emphasize preventative measures to minimize decline in ADL performance, including bathing, dressing, transferring, toileting, and feeding. For patients already experiencing ADL impairments, restorative guidelines aim to help them regain independence and inform further evaluations by physical and occupational therapists or care managers. These protocols strongly emphasize patient mobility, ADL function, specific nutritional goals, skin integrity, urinary and bowel continence, cognitive function (maintaining normal sleep-wake cycles and delirium prevention), and sensory augmentation (hearing and vision).
Table 2 outlines the key contributions of team members during interdisciplinary rounds. These daily meetings typically last about 30 minutes, aiming to review approximately 10 patients, including all new admissions. New patient discussions average 5 minutes, while follow-up patients are discussed in 1–2 minutes. While not all team members can attend daily rounds, the core team includes the bedside nurse, clinical nurse specialist/geriatric resource nurse, and care manager. Other team members, when available, include the attending physician, geriatrician, and clinical pharmacist. Extended team members may include physical and occupational therapists, dietitians, and speech-language therapists. The advanced practice nurse acts as the central coordinator, ensuring care plan consistency and communication among team members, patients, and providers. Team rounds reinforce bedside nursing care and clarify goals, patient preferences, prognosis, and specialist recommendations. Geriatricians may mediate care plan discrepancies between the attending physician, interdisciplinary team, or specialists. The foundational ACE principles of patient-centeredness, safety, and physical independence guide all team recommendations.
Table 2. Interdisciplinary Team Members, Tasks and Roles.
| Member | Tasks/Roles |
|---|---|
| Physician and/or bedside nurse | – Admitting diagnosis or problem: key findings – Relevant past medical history – Treatment plans – Anticipated length-of-stay and postacute site of care |
| Bedside nurse (report) | – Assess baseline and current functional status: ADL, mobility, mood/affect, cognition, living situation, social support, nutritional status (role shared with physician) – Implement preventative/restorative protocols |
| Care coordinator/social worker | – Identify resources (caregiving, finances, options) – Coordinate discharge (transitions) options – Order durable medical equipment |
| Clinical pharmacist | – Assess medication appropriateness (potentially inappropriate medications) (shared role with physician) – Plan for monitoring of high risk medications |
| Physical therapist | – Mobility assessment (shared role with bedside nurse) – Transfer and gait assessment with recommendations – Determine need for skilled services (rehabilitation) |
| Occupational therapist | – Assess need for ADL devices/aids – Evaluate physical functioning – Determine need for skilled services (rehabilitation) |
| Dietitian | – Assess baseline nutritional status – Offer dietary recommendations – Work with speech therapy in assessment of oral feeding |
| Summary: Interdisciplinary team | – Estimate functional trajectory – Estimate length of hospital stay – Estimate postacute requirements – Review quality of care and safety – Plan for care transitions |
| Patient and family (medical power of attorney) | – Review goals of care, personal preferences, advance directives – Engage in self-care – Share decision-making with ACE team |
During team rounds, a functional trajectory is developed, outlining the patient’s current functional status, baseline function (typically two weeks pre-admission), and pre-illness social support network. This trajectory includes a review of baseline ADL and instrumental ADL performance, mobility, cognitive function, mood, living situation, social supports, and advance directives.
Baseline functional status is compared to the admission functional assessment, based on nurse and physician evaluations of basic ADLs, cognition (delirium, dementia), mood (anxiety, depression), and nutritional status (oral intake).
The interdisciplinary team implements patient-centered care, potentially including physical therapy, occupational therapy, medication review, nutritional support, and care coordination. The goal is to return patients to their baseline physical functioning by discharge.
The daily objective is to enhance independent ADL performance and mobility, ensuring clinical stability and safe return home, or arranging appropriate social supports for caregiving. Alternatively, recommendations for post-acute rehabilitation or long-term care facilities are considered. The functional trajectory is reviewed and adjusted daily during team rounds.
3.3. The Pivotal Role of Physical Functioning in Elderly Care
The link between baseline functioning and the need for post-acute care was confirmed in a secondary analysis of the first ACE unit trial. The study highlighted that the oldest patients, particularly those over 90, were most prone to ADL decline.
Cognitive function receives special attention, recognizing the risk of functional decline associated with delirium prevalence.
Identifying depression, though challenging in acutely ill older patients, is considered vital, as it is linked to functional decline and increased 3-year mortality.
Severe medical illness and multiple chronic conditions often inform the team about prognosis and the appropriateness of transitioning to comfort care or hospice.
Team-initiated family/patient conferences are held when clinical pathways are uncertain, when transitioning to comfort measures, or to review patient goals of care. Subsequent ACE cohort analyses identified six independent predictors of 1-year mortality among hospitalization survivors, including ADL function, which has become a widely used predictive tool. In all ACE units, the geriatric assessment of ADL function, mood, cognition, and medical conditions is initially conducted by the attending physician and bedside nurse. Bedside nurses benefit from geriatric resource nurse training and NICHE online modules.
Mobility status is arguably the most critical bedside assessment, as it dictates ADL performance, weight-bearing ability, ambulation, and assistive device use. Low mobility during hospitalization correlates with functional decline in older adults, and even in healthy older adults, bed rest rapidly diminishes muscle strength and mass. Immobility is a well-recognized hospitalization hazard. Acutely ill older adults are often fatigued or cognitively impaired, limiting their ability to participate in physical activities. Nurses use guidelines to perform passive or active range of motion exercises and frequent repositioning to maintain skin integrity and conditioning until patients can be further mobilized, potentially using lifts or straps for transfers. Some hospitals and ACE units utilize lift teams to facilitate patient transfers. While improving patient mobility requires significant effort, the benefits for nursing staff are substantial, as patients are less likely to develop immobility-related complications and persistent bed rest issues. For example, immobility is a recognized risk factor for urinary catheterization, with its associated adverse consequences like infection, when not clinically indicated. Patients reporting unsteadiness at admission are also more likely to experience functional decline by discharge. Studies from ACE unit trials highlight the importance of independent physical functioning during and after hospitalization. Failure to regain ADL independence lost during hospitalization is linked to a higher risk of further functional decline, institutionalization, and mortality. ACE unit trial data has been used to develop a clinical index to stratify hospitalized older patients based on their risk of new-onset ADL disability. Ten factors, readily available within 24 hours of admission, independently predict ADL decline by discharge. Combining data from multiple ACE unit studies allows estimation of ADL independence recovery, dependence, or mortality in elders who become disabled during hospitalization. This information is clinically valuable for physicians and teams, especially in discussions about goals of care and prognosis. While these indices haven’t been prospectively studied in trials, their robust findings suggest clinical utility.
3.4. Proactive Planning for Transition to Home (Discharge Planning)
In ACE units, discharge planning begins on admission day, guided by the assumption that patients living at home should return home, following their functional trajectory. Original ACE unit studies did not focus on post-acute care transitions, but recognized patient stability and functioning as key to safe transitions. Patient-centric ACE components are crucial in minimizing post-acute placement and unplanned readmissions. Funding and resource limitations prevented ACE unit studies from including post-acute transition interventions. However, other researchers have developed evidence-based transition models that, combined with ACE interventions, could potentially enhance patient benefits and reduce readmission rates. Acute and transitional care interventions are increasingly adopted by hospitalists in quality improvement programs.
3.5. Medical Care Review and Geriatric Expertise
In many ACE units, geriatricians or advanced practice nurses primarily educate and mentor interdisciplinary teams, bedside nurses, support staff, and attending physicians using academic detailing techniques. Medical review includes quality measure oversight and adherence to current best practices. It also helps resolve care direction conflicts among team members or between the team and specialists. For instance, an interdisciplinary team might recommend comfort care and hospice for a frail patient with advanced illness, while specialists may advocate for aggressive, disease-focused interventions. Team leaders can advocate for the patient and family’s perspective when it differs from specialists. This advocacy extends to ensuring patients receive evidence-based treatments. For example, in cases of atrial fibrillation, physician detailing can provide evidence-based arguments for anticoagulation, balancing benefits and risks. Interdisciplinary team meetings ensure consistent messaging when discussing complex issues with patients and families.
Medication review, in collaboration with clinical pharmacists, is a vital leadership contribution in ACE units. Teams refer to guidelines for appropriate prescribing of potentially inappropriate or high-risk medications. Diagnostic and therapeutic procedures are evaluated for necessity and alignment with patient goals and clinical guidelines. Early ACE units focused on psychoactive and anticholinergic medications. The ACE tracker tool efficiently informs teams about functional and clinical issues, including potentially inappropriate prescribing. It provides a patient-specific spreadsheet with data on length of stay, falls risk, ischemic injury risk, inappropriate medication use (especially antipsychotics), mobility risk score, ADL status, advance directives, and readmission history. The ACE tracker is invaluable for quality improvement and documenting high-risk patient characteristics and treatments.
Medical care review includes implementing protocols to minimize adverse effects of procedures, using environmental interventions (safe rooms), family/sitter presence, parenteral alimentation guidelines, and ischemic injury prevention and treatment. Nurse and physician information is enhanced by team evaluations and recommendations.
4. Evidence of ACE Unit Effectiveness: Results from Clinical Trials
Three randomized clinical trials have evaluated ACE units, each adhering to the original model but varying in objectives, protocols, outcome measures, and settings. Two trials were at a tertiary care teaching hospital in Cleveland, Ohio, and one at a community hospital in Akron, Ohio.
4.1. First Trial at University Hospitals of Cleveland
The first randomized trial enrolled 651 patients aged 70+ admitted to general medical units for acute illnesses. Randomization occurred in the emergency department, assigning patients to usual care or ACE unit care. The ACE unit had 15 beds for geriatric patients, but only a subset participated in the trial. Trained research assistants interviewed patients and families, collecting data on baseline and admission functional status, cognition, mobility, caregiver strain, living situation, mood, and perceived health. Clinical data included hospital costs, length of stay, and post-discharge telephone interviews. Deaths were verified via national death index and hospital records. The primary outcome was performance in five ADLs from admission to discharge. ACE unit patients received usual care under attending and resident teams, with similar nursing budgets to usual care units. Significant physical environment changes were made in the ACE unit, including a patient socialization area. Independent performance in bathing, dressing, transferring, toileting, and eating were assessed as individual ADL items.
At discharge, intervention group patients showed significantly better ADL performance and were less likely to be worse in ADLs compared to controls. Length of stay and hospital costs showed small, non-significant differences. ACE unit patients were significantly less likely to transition to post-acute facilities compared to usual care patients. Cost analysis showed total costs, including unit renovation and personnel support, were not significantly different from usual care. No differences in post-acute mortality or ADL function at 90 days were observed between groups.
4.2. Trial at Akron City Hospital
The second randomized trial included 1531 patients, with longer-term follow-up, comparing usual care medical-surgical units to ACE unit care. Many ACE unit patients were managed by private physicians without resident teams, unlike the first study. Similar interdisciplinary team-based care was implemented in a 34-bed renovated unit. Patient, caregiver, physician, and nurse satisfaction surveys were conducted. The primary outcome was ADL performance from baseline to discharge. No statistically significant differences in ADL performance were found between ACE and usual care groups. However, a composite outcome of ADL decline or nursing home placement was less frequent in the intervention group at discharge and one year post-discharge. Satisfaction was higher in the intervention group for both patients and providers. Mobility scores were higher in the ACE group. Process of care measures, including restraint use, were significantly better in the ACE unit. Hospitalization costs were similar in both groups.
4.3. Second Trial at University Hospitals of Cleveland
The third randomized trial enrolled 1632 patients, maintaining ACE program fidelity. The larger sample size allowed better assessment of length of stay and cost outcomes. During the trial, usual care units moved to a new hospital tower resembling the ACE unit environment, possibly influencing results. No effect on ADL function was found between ACE and usual care. However, ACE unit patients had significantly shorter hospital stays and lower per diem and total care costs. Substantially lower inpatient costs per patient were observed while maintaining ADL independence and not increasing readmission rates. While hospital payments were not measured, shorter stays suggest greater revenue vs. costs for the hospital in the ACE Unit.
4.4. Summary of ACE Unit Trial Evidence
These three trials suggest enhanced patient care efficiency at lower costs, with trends supporting reduced functional disability in ACE units. A systematic review and meta-analysis of acute geriatric units confirmed benefits of shorter stays, fewer nursing home discharges, and lower costs.
A retrospective study of hospitalists’ patients aged 70+, comparing ACE and usual care units, found significantly lower total costs and 30-day readmissions for ACE unit patients, supporting earlier findings of lower ACE unit costs.
Other acute hospital care models, like the Hospital Elder Life Program (HELP), show promise. HELP focuses on delirium prevention using elder life specialists and volunteers and is cost-effective for moderate-risk patients. HELP has been widely adopted and integrated with ACE units in some hospitals.
ACE unit trials enrolled patients aged 70+ from general medical units, not surgical or intensive care units. Limited data exists on ACE unit effectiveness for patients under 70 or the broader applicability of ACE principles to all adult general medicine patients. If cost analyses are similar in younger patients, the low intervention cost suggests potential benefits for all acutely ill patients admitted from home in preventing functional decline.
No studies have identified subgroups most likely to benefit from ACE units. The low intervention cost lessens the need for targeting, offering hospitals flexibility in patient selection. Original ACE studies unsuccessfully attempted to exclude nursing home patients, assuming they would benefit least due to baseline ADL disability.
5. Barriers to Wider ACE Unit Dissemination
Despite the demonstrated benefits, ACE unit dissemination has been limited. The ACE model prioritizes function, environment, interdisciplinary expertise, and post-acute needs, contrasting with the biomedical model’s focus on physician-led medical decision-making and acute illness. The ACE model requires a cultural shift in usual care. Without strong financial incentives in fee-for-service Medicare, hospital leaders focused on revenue streams have limited motivation to adopt non-immediately revenue-generating programs, even with evidence of improved quality and reduced total costs. The benefits of ACE are often overlooked despite regulatory and financial pressures to reduce readmissions and hospital-acquired conditions. The emphasis on a “unit” model has been misinterpreted, while older patients are increasingly admitted across all hospital units, raising questions about single-unit investments. However, the ACE intervention was always intended to be scalable, with successful components adopted hospital-wide. While scaled ACE programs exist, evidence-based research is limited. A misperception persists that ACE is a complex intervention, while in reality, it is older patients who are complex, requiring a different care model with interdisciplinary teams.
ACE is both a continuous quality improvement and patient safety program. Mature ACE programs develop highly skilled healthcare professionals capable of delivering efficient, cost-effective care to complex patients. As healthcare shifts towards value-based care, ACE may regain prominence.
Geriatrician shortages, especially in acute care, pose a challenge. A growing number of hospitalists are geriatrics-trained and committed to ACE-like quality improvement. Geriatricians primarily provide medical review and team education, but advanced practice nurses can also lead ACE units. Lack of gerontology and geriatric training among healthcare professionals is a significant barrier. Untrained providers may overlook critical issues or make diagnostic errors. Finally, a lack of standardized ADL measurement across hospitals hinders progress. Hospital and physician reimbursement is not linked to patient functional status changes. Until ADL measurement consensus and regulatory changes reward functional improvement, ACE unit dissemination will remain limited. The evidence clearly shows predictable and partially preventable functional disability, causing persistent deficits and reduced quality of life post-hospitalization – termed “post-hospital syndrome.”
6. Conclusions and Future Directions
The ACE unit model has evolved, reflecting broader trends in acute hospital care for adults. Physical environments are becoming more ACE-like, clinical pharmacists are monitoring medications, financial incentives are driving reductions in hospital-acquired conditions common in older adults, and transition planning is more prevalent. Demographic trends favor seniors, suggesting acute hospital care will continue to improve, with ACE providing a valuable roadmap for the future.
Funding: This research received no external funding.
Conflicts of Interest: The authors declare no conflict of interest.
References: (List of references from the original article would be included here in a full version, but is omitted for brevity as per instructions).
