Older adults face a significant risk of losing their ability to care for themselves when hospitalized for acute illnesses. To address this, the Acute Care for Elders (ACE) program was developed as a model for continuous quality improvement. The primary goal of Acute Care Of The Elderly Program is to prevent hospital-associated disability, ensuring older patients maintain their independence in daily activities from the moment they are admitted until they are discharged. The ACE program achieves this through a combination of strategies: creating a supportive environment for self-care, implementing clinical guidelines for healthcare professionals, and carefully planning the transition of care. This structured approach involves an interdisciplinary team conducting comprehensive geriatric assessments, adhering to clinical guidelines, and collaboratively planning care transitions with patients and their families. Research, including randomized clinical trials and systematic reviews, has consistently demonstrated the effectiveness of the ACE model and similar interventions. These studies show that acute care of the elderly program leads to reduced functional disability, lower rates of nursing home admissions, and decreased hospitalization costs. The core principles of ACE can be applied to enhance elderly care across various acute care settings. This article will explore the ACE model in detail and explain the reasons behind its success in improving outcomes for older hospitalized patients.
1. Understanding the Foundation of the ACE Program
The acute care of the elderly program, known as the ACE model, was specifically designed to minimize functional decline in older adults during hospital stays for acute medical conditions [1]. The ACE unit, a dedicated medical-surgical unit, was the setting for this intervention. Its aim was twofold: to prevent loss of independence in Activities of Daily Living (ADLs) and to help patients regain any ADL independence lost during their illness and hospitalization by the time they were discharged. The ACE program integrates continuous quality improvement principles with comprehensive geriatric assessment to create an improved care system for older patients experiencing acute illness [2]. This multifaceted approach includes four essential components: a purposefully designed physical environment that promotes both functional independence and patient safety; patient-centered care delivered at the bedside by registered nurses in collaboration with a diverse team of healthcare professionals; comprehensive discharge planning initiated early in the hospitalization and guided by the interdisciplinary team; and thorough medical care review to ensure optimal medication management and clinical care.
Prior research has consistently highlighted the dangers of iatrogenic illness, the negative impacts of immobility and prolonged bed rest, often referred to as the “hazards of hospitalization” [3,4]. Studies examining the progression of functional problems in older hospitalized individuals revealed that a significant number experience a decline in independence from their pre-hospitalization functional level by the time they are discharged, underscoring the detrimental effects of hospitalization [5,6]. Smaller-scale clinical trials indicated that modifying the hospital environment and utilizing interdisciplinary teams could lead to significant improvements in patient outcomes [1,7]. In developing the ACE model, researchers focused on creating an environment that could safely support patients’ individual needs and abilities. A patient-focused approach is facilitated by an interdisciplinary team skilled in assessing and enhancing the physical functioning of older adults during acute illness. Funding from the John A. Hartford Foundation enabled researchers to develop, implement, and evaluate the ACE unit, assessing its impact on physical functioning, specifically basic ADLs [8]. They also examined secondary outcomes such as care costs, length of hospital stay, self-reported mobility, and transitions to nursing facilities or home. While cost-effectiveness was not the primary focus, the ACE program was designed to be cost-neutral. Three randomized clinical trials of the ACE unit were conducted with slightly different objectives but consistently adhered to the core principles and incorporated practical adaptations reflecting a continuous quality improvement approach. These trials compared standard care on medical-surgical units with the ACE unit model of care.
This commentary aims to provide a detailed description of the ACE model and explain the reasons for its effectiveness in acute care of the elderly program. We will review the conceptual underpinnings of the ACE intervention, the clinical trial evidence supporting its benefits over traditional care, lessons learned from these experiences (including obstacles to wider adoption), and future directions for acute care models for older adults. These insights are even more relevant today than when the ACE model was first introduced in the 1990s. The aging population in America is growing, older adults are hospitalized more frequently and for longer durations than younger patients, most hospitalized seniors have multiple chronic conditions, the number of medical procedures performed on older adults is increasing, and hospitalization costs covered by Medicare continue to rise [9,10].
Conceptual Basis
Acute illnesses can be particularly stressful for older adults and their families. Already managing acute health issues and often multiple chronic conditions, aspects of hospitalization itself, such as an unfamiliar and potentially unsafe environment and typical care processes (like restricted mobility), can contribute to a decline in functional independence. It can also hinder the restoration of physical function to pre-illness levels. The original concept of “dysfunctional syndrome,” now termed hospital-associated disability [11], posits that reduced physiological reserves and multiple chronic conditions make older patients more susceptible to functional decline. Age-related loss of muscle mass, strength, and aerobic capacity can be further exacerbated by the deconditioning effects of immobility, postural instability, impaired blood pressure regulation (leading to orthostatic hypotension), and new physical impairments. These factors can also negatively impact cognition, potentially causing delirium, anxiety, or depression. Furthermore, traditional, compartmentalized hospital care often excludes patients and families from active participation in the recovery process and the return to independent living [12]. Hospital-acquired conditions, such as falls with injuries, delirium, pressure ulcers, and catheter-associated urinary tract infections, are common in patients over 65 and are often preventable. A negative hospital environment, prolonged bed rest, inadequate nutrition, immobility, and a lack of personalized care all increase the risk of functional decline, potentially leading to a disabled state upon discharge. However, interventions aimed at disrupting this cycle of decline can improve hospital outcomes by mitigating these adverse effects. Enabling patients to walk, engage in self-care, interact socially, sleep adequately, and maintain good nutrition are crucial aspects of recovery [13]. Immobility, in particular, poses a significant threat to functional status and the ability to perform essential ADLs like transferring and walking. The ACE Unit was developed to systematically interrupt and reverse hospital-associated disability, while also enhancing patient flow and promoting patient-centered care in the acute care of the elderly program.
2. Building the ACE Unit: A Transformative Approach
Implementing an acute care of the elderly program like the ACE unit represents a significant shift in hospital culture regarding the care of older adults. The focus moves from treating individual diseases to caring for the whole patient. A successful ACE program requires adapting the physical environment to support functional independence and safety, and transitioning from multidisciplinary to truly interdisciplinary team-based care. This transformation benefits from a business-oriented strategy that demonstrates the value of the ACE unit to hospital leadership, highlighting the return on investment and enhanced institutional reputation. A phased approach can guide the implementation of ACE unit components and inform a practical business plan [14,15]. However, securing buy-in from upper management is essential, as the costs of unit modifications and staff retraining can be substantial. While research indicates that ACE units do not increase overall hospitalization costs [16], initial investments in staff training and unit upgrades might be necessary, especially in older facilities. For instance, the first ACE unit at University Hospitals of Cleveland was established in an older medical-surgical unit with 15 beds dedicated to geriatric patients. This unit required significant renovations, funded externally, to create the supportive environment. It’s worth noting that many of the design features incorporated into the first ACE Unit are now standard in newly built or renovated community hospitals.
Once hospital leadership commits to establishing an ACE unit for their acute care of the elderly program, an advisory council composed of leaders from relevant departments is formed. This council guides program development and fosters interdisciplinary team collaboration. In the original ACE unit, each department director contributed to creating patient care guidelines tailored for complex older adults. An advisory council also promotes strong collaboration among team members and champions high-quality care for older patients [15,17]. Subsequently, the council meets regularly to assess the ACE unit’s progress and review performance metrics that demonstrate return on investment, such as hospital costs, quality indicators, and prevention of hospital-acquired conditions. This collaborative approach ensures that all healthcare providers share ownership of the ACE unit and become advocates for its sustainability and growth within the acute care of the elderly program.
2.1. The Prepared Environment
The design of the first ACE unit was informed by insights from architectural design in acute and long-term care facilities, inpatient rehabilitation programs, and the practical experiences of clinicians and researchers [1]. To create a more homelike atmosphere and minimize risks of falls, confusion, anxiety, and deconditioning, the original unit incorporated several key features. Carpeting was installed, handrails were added in hallways, corridors were kept clear of clutter, and earth-tone wallpaper and paint with contrasting colors between floors, walls, and ceilings were used to aid depth perception for patients with visual impairments [17]. Diffuse lighting, including wall sconces and lighting behind patient beds, was implemented. Lever-style door handles were installed, and large clocks and calendars were placed to assist with orientation. Bathrooms were equipped with elevated toilet seats, and wall hangings and carpeting helped reduce noise levels [1,2]. A designated communal space was created to encourage patient and family socialization. While these were innovative features in the 1990s, many hospitals today incorporate these design elements, although synthetic flooring is often preferred over carpeting. The increasing emphasis on wellness, calming environments, privacy, and noise reduction in modern hospital design reflects market trends and a focus on enhancing patient satisfaction and safety [18]. As hospital designs become more “senior-friendly,” medical units are increasingly aligned with the ACE principles of a prepared environment. This reduces the need for extensive retrofitting of medical-surgical units, which was a significant cost in earlier ACE unit implementations for acute care of the elderly program. Current hospital designs must also comply with the Americans with Disabilities Act (ADA) (https://www.ada.gov/), which mandates room specifications that are highly compatible with the prepared environment concept of ACE units (see Table 1). Moreover, these design features are generally well-received by most adult patients, suggesting that future medical unit designs should ideally resemble the ACE Unit model. The prepared environment exemplifies a safety culture where preventing hospital-acquired conditions is integrated with preventing immobility, acute confusion, and geriatric syndromes within the acute care of the elderly program. It can be argued that the design principles of ACE Units should become standard practice in all new hospital construction and nursing unit upgrades [19].
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 to 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 |
2.2. Patient-Centered Care
Patient-centered care, a cornerstone of acute care of the elderly program, is defined as “care that is respectful of, and responsive to, individual patient preferences, needs, and values, ensuring that these values guide all clinical decisions” [20]. This approach acknowledges patients’ cultural backgrounds, personal preferences, values, and the needs of their families, integrating them as active members of the interdisciplinary team in clinical decision-making. In ACE units, healthcare providers with a special interest in geriatric care share responsibility with the attending physician for patient management and team interactions. In this interdisciplinary team-based care model, health professionals collaborate and communicate effectively with each other, as well as directly with patients and families. Unlike traditional, siloed multidisciplinary care, ACE team members prioritize necessary professional services, leading to greater efficiency in care delivery. Recommendations are based on agreed-upon standards of practice for patients within the acute care of the elderly program.
The ACE unit model greatly benefits from the central role of nurses, who provide continuous bedside care, and advanced practice nurses, who typically lead interdisciplinary rounds and maintain daily communication with attending physicians and consultant geriatricians. Many ACE units have trained geriatric resource nurses and are often affiliated with Nurses Improving Care of Healthcare Systems for Elders (NICHE) [21]. Under the guidance of advanced practice nurses and with support from geriatric resource nurses, primary bedside nurses receive training in specific guidelines (protocols) for caring for older adults at the bedside. These protocols include preventive strategies aimed at minimizing declines in patients’ ADL performance: bathing, dressing, transferring, toileting, and eating. For patients already experiencing ADL impairments, restorative guidelines are implemented to help them regain independent functioning and to inform further evaluations by physical and occupational therapists or care managers. These protocols heavily emphasize patient mobility, ADL function, specific nutritional goals, skin integrity, urinary and bowel continence, cognitive function (including maintaining normal sleep-wake cycles and preventing delirium), and optimizing sensory function (hearing and vision) [17].
Table 2 outlines the key contributions of team members during interdisciplinary rounds within the acute care of the elderly program. 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 patient reviews take 1-2 minutes. Realistically, not all team members can attend every daily round. The core team usually includes the bedside nurse, the clinical nurse specialist/geriatric resource nurse, and the care manager. Other team members, when available, include the attending physician, a geriatrician (if involved), and a clinical pharmacist. Extended team members may include physical and occupational therapists, dietitians, and speech-language therapists. The advanced practice nurse acts as the coordinator, ensuring communication among team members, consistency in care plans, and updates for patients and providers. Team rounds reinforce bedside nursing care and clarify patient goals, prognoses, and specialist recommendations. Geriatricians may sometimes mediate differing care plans between the attending physician, the interdisciplinary team, or specialist physicians. The ACE principles of patient-centeredness, patient safety, and independent physical functioning are fundamental to the team’s recommendations in the acute care of the elderly program.
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 these rounds, the interdisciplinary team develops a functional trajectory, which maps the patient’s current functional status against their baseline function (typically assessed as two weeks prior to admission) and their pre-illness social support network [22]. This trajectory includes a review of the patient’s pre-hospitalization independence in basic and instrumental ADLs, mobility, cognitive function, mood, living situation, social supports, and the presence of advance directives.
The baseline functional status is compared to the admission functional assessment, which is based on the nurse’s and attending clinician’s evaluation of basic ADLs, cognition (delirium, dementia), current mood (anxiety or depression), and nutritional status (oral intake).
The interdisciplinary team then implements patient-centered care strategies as part of the acute care of the elderly program, which may include physical therapy, occupational therapy, medication review by a geriatrician or pharmacist, nutritional support, and care coordination. The team aims to help the patient return to their baseline physical functioning level by hospital discharge.
The daily objective is to enhance the patient’s independent performance of ADLs and mobility, ensure clinical stability, and determine if they are clinically ready for a safe return home with adequate social support. If returning home is not feasible, the team recommends an appropriate post-acute care setting, such as a rehabilitation facility or long-term care facility. The functional trajectory is reviewed and adjusted daily during team rounds as needed within the acute care of the elderly program.
2.3. The Vital Role of Physical Functioning
The importance of baseline functional status in predicting post-acute care transitions was confirmed in a secondary analysis of the first ACE unit trial [23]. The team recognized that the oldest patients, particularly those 90 and older, were most vulnerable to ADL decline, as highlighted in a subsequent analysis [24].
Cognitive function is also closely monitored, with a strong awareness of the functional decline risks associated with delirium [25].
Detecting depression, although challenging in acutely ill and complex older patients, is considered crucial by the team, as it has been linked to functional decline and an increased risk of 3-year mortality [26,27].
Severe medical illness and multiple chronic conditions often provide the interdisciplinary team with insights into a patient’s prognosis and the appropriateness of shifting from aggressive interventions to palliative or hospice care within the acute care of the elderly program.
Team-initiated family/patient conferences are held when clinical pathways are uncertain, when considering a transition to comfort measures, or when reviewing patient care goals. Further analysis of ACE cohorts has identified six independent predictors of 1-year mortality among hospital survivors, including ADL function. This predictive index has become a widely used tool [28]. In all ACE units, the geriatric assessment of ADL function, mood, cognition, and acute and chronic medical conditions is initially the responsibility of the attending clinician and bedside nurse. Bedside nurses today benefit from training as geriatric resource nurses and participation in NICHE online modules [21].
Arguably, the most critical bedside assessment performed by nurses and the team is mobility status. Mobility is a key determinant of a patient’s ability to perform ADLs, bear weight, walk, or use assistive devices. Reduced mobility during hospitalization is strongly correlated with functional decline in older adults [29], and even in healthy older adults, bed rest leads to rapid declines in muscle strength and mass [30]. Immobility has long been recognized as a significant hazard of hospitalization [4]. Acutely ill older adults are often fatigued or cognitively impaired, limiting their ability to participate in physical activities. Nurses, guided by protocols in the acute care of the elderly program, perform passive or active range-of-motion exercises and frequently reposition patients to maintain skin integrity and conditioning until they can be mobilized more actively, often using lifts or straps to assist with transfers. Some hospitals and ACE units utilize lift teams to facilitate patient transfers. While significant effort may be needed to improve patient mobility, the benefits for nursing staff are substantial, as patients are less likely to develop complications from immobility and prolonged bed rest. For example, immobility is a well-established risk factor for urinary catheterization in medically ill patients, along with the adverse consequences of prolonged catheter use, such as urinary tract infections, when not clinically indicated [31,32]. Patients who report unsteadiness upon hospital admission are also at higher risk of functional decline by discharge [33]. Further studies of patients in ACE unit trials have highlighted the crucial role of independent physical functioning during and after hospitalization in the acute care of the elderly program. One analysis showed that failure to regain ADL independence lost during hospitalization was associated with an increased risk of further ADL decline, institutionalization, and death [34]. Using data from ACE unit trials, researchers have developed a clinical index to stratify hospitalized older patients based on their risk of new-onset ADL disability. This index includes 10 readily available items within 24 hours of admission that are independently linked to ADL independence loss and are highly predictive of functional decline by hospital discharge [35]. By combining data from multiple ACE unit studies, predictions of ADL independence recovery, dependence, or death in older adults who become disabled during hospitalization can be estimated [36]. This information is clinically valuable for physicians and care teams, particularly when discussing care goals and prognosis with patients. While these indices are not yet prospectively studied in clinical trials, their findings are robust and indicate their potential as valuable clinical tools within the acute care of the elderly program.
2.4. Planning for a Smooth Transition Home
In ACE units, discharge planning, or planning for the patient’s transition back home, begins on the first day of admission. The team operates under the assumption that if the patient was living at home prior to admission, the goal is to facilitate their return home, guided by the functional trajectory. The original ACE unit studies did not primarily focus on post-acute care transitions, but the team recognized that patient clinical stability and physical functioning were crucial for a safe transition. The patient-centered components of the ACE intervention are particularly important in reducing the risks of post-acute institutional placement or early hospital readmissions. Funding limitations and scarcity of post-acute care resources prevented the ACE unit studies from including interventions specifically targeting post-acute transitions. However, other researchers focusing on care transitions have developed evidence-based models that, when combined with the ACE unit intervention, could potentially yield even greater benefits and reduce hospital readmission rates in the acute care of the elderly program [37,38]. Crucially, acute care and transitional care interventions have been increasingly adopted by hospitalists in quality improvement initiatives.
2.5. Medical Care Review: Ensuring Best Practices
In many acute care of the elderly programs like ACE units, a key role of geriatricians or advanced practice nurses is to educate and mentor interdisciplinary team members, bedside nurses, support staff, and attending physicians through academic detailing [39]. Medical review includes monitoring quality measures and metrics and ensuring adherence to current best practices. It also helps to resolve conflicts in care direction that may arise among team members or between the team and specialist providers. For instance, an interdisciplinary team, after engaging with the patient and family, might recommend palliative care and hospice for a frail patient with a serious illness, while subspecialists might advocate for invasive procedures in an attempt to cure a single disease. The team leader can then act as an advocate for the patient and family, whose preferences may differ from the specialist’s, and facilitate communication. This advocacy role also extends to situations where patients are not receiving evidence-based treatments. For example, an attending physician might hesitate to prescribe anticoagulants for a patient with atrial fibrillation and stroke risk factors due to a perceived high risk of bleeding and falls. Physician detailing could then provide evidence-based arguments for anticoagulation, emphasizing the benefits over risks for that individual patient within the acute care of the elderly program. Interdisciplinary team meetings are essential for ensuring consistency in the views of team members when communicating with patients and families about complex or sensitive issues.
Medication review, conducted in collaboration with clinical pharmacists and other team members, is a vital aspect of leadership in the ACE unit and acute care of the elderly program. The team may consult guidelines for appropriate prescribing of potentially inappropriate medications or high-risk medications based on evidence-based literature. Similarly, diagnostic and therapeutic procedures are evaluated for necessity and alignment with patient goals, preferences, and established clinical guidelines. In early ACE units, psychoactive and anticholinergic medications were a particular focus. Subsequently, the development of an ACE tracker has streamlined the process of informing the interdisciplinary team about functional and clinical issues, including potentially inappropriate medication prescribing relevant to acute hospital care [40]. The ACE tracker is a spreadsheet containing patient information such as length of stay, fall risk, ischemic injury risk, use of potentially inappropriate medications (particularly antipsychotics), mobility risk score, ADL status, presence of advance directives, and history of hospital readmissions. The ACE tracker serves as an invaluable quality improvement tool and for documenting high-risk patient characteristics and treatments within the acute care of the elderly program.
Medical care review also involves implementing protocols to minimize adverse effects of specific procedures, ranging from environmental modifications like creating a safe room, involving family members or sitters at the bedside, guidelines for parenteral nutrition, and prevention and treatment of ischemic injuries [15,17]. Information from nurses and attending physicians is reviewed and enhanced through team evaluations and recommendations, ensuring comprehensive and coordinated care within the acute care of the elderly program.
3. Evidence of ACE Unit Effectiveness: Proven Results
Three randomized clinical trials have evaluated the effectiveness of ACE units as acute care of the elderly programs. Each trial adhered to the core ACE unit model but varied in primary objectives, protocol documentation, outcome measures, and clinical settings. Two studies were conducted at a tertiary care teaching hospital in Cleveland, Ohio, and the third at a community hospital in Akron, Ohio.
3.1. University Hospitals of Cleveland: Trial 1
The first randomized trial of the ACE unit enrolled 651 patients aged 70 and older admitted to general medical units for acute illnesses [2]. Randomization occurred in the emergency department, assigning patients to either usual care on general medical units or care on the ACE unit. The ACE unit allocated 15 beds for geriatric patients, with a subset participating in the trial. Trained research assistants interviewed patients and families to collect data on baseline and admission functional status, cognitive assessment, mobility, caregiver strain, living situation, mood, and perceived health. Clinical data from medical records included hospital costs, length of stay, and telephone interviews post-discharge. Deaths were confirmed via national death index and hospital records. The primary outcome was ADL performance from admission to discharge, measured across five ADLs. Patients on the ACE unit received standard medical care under an attending and resident team, with similar nursing budgets in both ACE and usual care units. Significant environmental modifications were made to the ACE unit, including a communal area for socialization, meals, and light exercise. Independent performance in bathing, dressing, transferring, toileting, and eating were assessed as individual ADL items within this acute care of the elderly program.
At discharge, patients in the ACE intervention group showed significantly better ADL performance compared to the control group and were less likely to experience a decline in ADL performance. While small, differences in length of stay and hospital costs were not statistically significant. Patients in the ACE unit were significantly less likely to be discharged to post-acute facilities compared to those receiving usual care, favoring a return to home. Cost analysis indicated that total costs, including unit renovation and personnel support, were not significantly different between ACE and usual care. No significant differences in post-acute mortality or ADL function at 90 days were observed between the groups in this acute care of the elderly program.
3.2. Akron City Hospital: Trial 2
The second randomized clinical trial involved a larger sample and longer-term follow-up, comparing outcomes for patients admitted to usual medical-surgical units versus an ACE Unit. Many ACE unit patients were managed by private physicians without resident teams, unlike the first study. A similar interdisciplinary team-based care model was implemented. Eligible patients were identified in the emergency department, and 1531 were enrolled [41]. The ACE intervention was delivered in a 34-bed renovated unit, maintaining consistency with the first study. Patient, caregiver, physician, and nurse satisfaction surveys compared ACE unit care to previous hospital experiences. The primary outcome was ADL performance from baseline to discharge. No statistically significant differences in ADL performance were found between ACE unit and usual care patients. However, a composite outcome of ADL decline or nursing home placement was less frequent in the intervention group at discharge and during the following year. Satisfaction with care was higher in the ACE intervention group for both patients and providers. Mobility scores were also higher in the ACE cohort. Process of care measures, such as absence of physical restraint use, were significantly better in the ACE unit. Hospitalization costs were similar in both groups in this acute care of the elderly program.
3.3. University Hospitals of Cleveland: Trial 3
The third randomized clinical trial enrolled 1632 patients, adhering to the key elements of the ACE program [42]. The larger sample size allowed for a more robust assessment of ACE’s impact on length of stay and cost outcomes. During the trial, usual-care units were relocated to a new hospital tower resembling the ACE unit’s physical environment, potentially influencing the intervention’s distinctiveness. The trial found no significant effect on ADL function between ACE and usual care units. However, length of stay was significantly shorter for ACE unit patients, and both per diem and total costs of care were significantly lower for ACE patients. Notably, substantially lower inpatient costs were achieved while maintaining patient ADL independence and without increasing hospital readmission rates. Although hospital revenues were not directly measured, the shorter length of stay suggests improved revenue-cost ratios for the hospital with the acute care of the elderly program.
3.4. Summary of ACE Unit Trials
The three clinical trials indicate that ACE units can enhance patient care efficiency at a lower cost, with evidence suggesting that functional disability, as measured by ADL performance, can be reduced through admission to an ACE unit as part of an acute care of the elderly program. A systematic review and meta-analysis of acute geriatric unit care for older adults further demonstrated significant benefits, including shorter hospital stays, fewer discharges to nursing homes, and reduced costs [43].
A retrospective cohort study comparing hospitalist patients aged 70 and older in ACE versus usual care units examined variable and direct costs. Total costs and 30-day readmission rates were significantly lower for ACE unit patients [44]. This study supports earlier findings of lower costs associated with ACE units compared to usual care in acute care of the elderly program.
Other acute hospital care models have emerged as promising alternatives to unit-based care [45]. ACE units share many objectives with the Hospital Elder Life Program (HELP) (https://www.hospitalelderlifeprogram.org), which focuses on preventing delirium in hospitalized older adults using elder life specialists and volunteers [46]. HELP is cost-effective for patients at moderate delirium risk and has been widely adopted, sometimes integrated with ACE unit care.
ACE unit trials primarily enrolled patients aged 70 and older from general medical units, excluding surgical or intensive care unit patients. Limited data exists on ACE unit effectiveness for patients younger than 70 or whether all general medicine patients would benefit from ACE features. If cost benefits are similar in younger patients, the low cost of the intervention suggests potential benefits for all acutely ill patients admitted from home in preventing functional decline through an acute care of the elderly program.
Finally, no study has identified specific patient subgroups most likely to benefit from ACE units. However, the low intervention cost makes targeted admission less critical, allowing hospitals and providers flexibility in selecting patients they believe will benefit most. Initial ACE unit studies unsuccessfully attempted to exclude nursing home patients, wrongly assuming they were least likely to benefit due to pre-existing ADL disability.
4. Barriers to Wider Adoption of ACE Units
“If ACE Units Are So Great, Why Aren’t They Everywhere?” “It’s not sexy stuff. In fact, it’s really quite routine care, involving communication and discharge planning that should be the norm for all hospitals trying to do what’s right for their patients” [47].
Despite the proven benefits, the widespread adoption of ACE as an intervention for acute care of the elderly program has been limited. As a care philosophy, ACE focuses on function, environment, interdisciplinary expertise, and the interplay of acute and chronic illnesses in post-acute needs. In contrast, the traditional biomedical model prioritizes physician-led medical decision-making and acute illness treatment, often overlooking environmental and functional aspects [48]. The ACE model requires a fundamental shift in the culture of usual care. Under fee-for-service Medicare reimbursement, hospitals lack strong financial incentives to implement programs like ACE that, while improving quality and reducing overall costs, are not immediately revenue-generating. The benefits of ACE, such as reduced readmissions and hospital-acquired conditions, are not always readily apparent to hospital leaders focused on immediate revenue streams, despite regulatory and financial incentives aimed at these areas. The emphasis on dedicated ACE units in early publications may also have inadvertently obscured the scalability of the ACE model, implying that investment in a single unit is required, while older patients are increasingly admitted across all hospital units. However, the ACE intervention was always intended to be scalable, with successful components adaptable across various hospital units [1]. While scaled ACE programs exist in the US, evidence-based research on their effectiveness is limited [48,49]. Perhaps the most significant barrier is the misperception that ACE is a highly complex intervention, whereas the reality is that older patients themselves are complex and require a different care model—including interdisciplinary teams—to address their multifaceted needs, a model not typically prevalent in standard hospital care.
This misperception overlooks that ACE is both a continuous quality improvement and a patient safety program for acute care of the elderly program. A fully implemented ACE program cultivates a highly trained, skilled, and competent healthcare workforce better equipped to provide efficient and cost-effective care to complex older patients who stand to benefit most from comprehensive care. As healthcare delivery evolves towards managed care, accountable care organizations, and bundled payment models emphasizing value-based care and shared savings, ACE principles may regain prominence [50,51].
Another challenge is the shortage of geriatricians in the US, particularly those specializing in acute care. A small but growing number of hospitalists are now trained in geriatrics and committed to quality improvement initiatives like ACE. The geriatrician’s role in ACE is primarily medical review and education for the interdisciplinary team and staff. Many ACE units can be effectively directed by advanced practice nurses. However, a broader lack of gerontology and geriatric practice training among healthcare professionals remains a significant issue. Providers without geriatric training may overlook critical aspects of care or make diagnostic errors. Finally, the absence of a universally adopted ADL measurement tool across hospitals hinders progress. Hospital and physician reimbursement is not directly linked to patient functional status or mobility changes during hospitalization. Until a consensus on ADL measurement and regulatory changes incentivize hospitals to account for improvements in physical function and mobility, the widespread dissemination of ACE units and effective acute care of the elderly program will remain limited. The evidence is clear: functional disability is predictable and partially preventable, leading to persistent deficits and reduced quality of life post-hospitalization for previously independent older adults [52,53]. This persistent morbidity and functional disability has been termed “post-hospital syndrome,” significantly impacting older people’s well-being [54].
5. Conclusions and Future Directions
The ACE unit model, an effective approach to acute care of the elderly program, has evolved in ways that reflect broader trends in acute hospital care for adults. Physical environments are increasingly incorporating “ACE-like” features, clinical pharmacists are actively monitoring potentially inappropriate medications, financial incentives are in place to reduce hospital-acquired conditions more prevalent in older adults (falls, pressure injuries, catheter-associated UTIs), and discharge planning is becoming more standard. Time and demographics favor older adults: acute hospital care will continue to improve, and ACE provides a valuable vision for this progress.
Funding
This research received no external funding.
Conflicts of Interest
The authors declare no conflict of interest.
