An 85-year-old who remains active and independent may recover from pneumonia more quickly than someone 20 years younger with multiple chronic illnesses, poor nutrition, and declining mobility.

Growing evidence suggests that frailty — a state of diminished physiologic reserve and increased vulnerability to stressors — is one of the strongest predictors of prolonged hospitalization, complications, functional decline, discharge to post-acute care, readmissions, and mortality, often outperforming chronological age alone. 

A 2024 review published in The New England Journal of Medicine described frailty as a key measure of physiologic reserve that can help clinicians individualize treatment decisions for older adults facing acute illness. Similarly, a 2023 systematic review of hospitalized patients published in eClinicalMedicine found that frailty was consistently associated with longer hospital stays, higher mortality, institutional discharge, and readmissions.

“When caring for hospitalized older adults, one of the greatest mistakes clinicians can make is allowing chronological age to define expectations for recovery,” said Leah Verebes, EdD, DPT, assistant professor in the School of Health Sciences at Touro University in New York City. “Age, by itself, tells us remarkably little about a person’s physiologic reserve, resilience, or ability to recover from acute illness.”

Instead, clinicians should focus on physiologic age rather than chronological age, she said.

“Rather than asking simply, ‘How old is this patient?’ clinicians should ask, ‘How resilient is this patient?’” Verebes said. Frailty reflects diminished physiologic reserve and increased vulnerability to stressors, leaving patients less able to recover from illnesses, surgery, or hospitalization.

Lindsey Ulin, MD, assistant professor of medicine at UT Southwestern Medical Center in Dallas and a palliative care physician, said hospitalists often recognize frailty but fail to consistently assess or document it.

“Frailty may not be why someone is admitted to the hospital,” Ulin said, “but it should change how we care for them.”

Screening Should Be Practical, Not Perfect

Although dozens of validated frailty assessment tools are available, experts said the goal is not to identify the perfect instrument but to consistently recognize patients with diminished physiologic reserve.

Verebes said the Clinical Frailty Scale can be completed in less than a minute and is particularly practical because it assesses patients according to their baseline mobility, cognition, function, and independence before hospitalization rather than their condition during an acute illness. She said hospitalists should score patients based on their prehospital level of function whenever possible.

“When feasible, performance-based measures provide objective information that complements subjective screening. Gait speed, grip strength, the Short Physical Performance Battery, and standardized mobility assessments can identify physiologic vulnerability before significant disability develops. Although performing every component of the Fried assessment may not always be practical,” she said.

The “Fried assessment” Verebes referred to is the Fried Frailty Phenotype, first described in 2001. It defines frailty using five measurable characteristics: unintentional weight loss, self-reported exhaustion, weakness measured by grip strength, slow walking speed, and low physical activity. Patients meeting three or more criteria are considered frail, while those meeting one or two are classified as prefrail.

However, Ulin said clinicians should avoid becoming preoccupied with selecting one screening instrument.

“The most important frailty tool is the one clinicians will actually use,” she said. Electronic health records — and increasingly, AI-enabled clinical decision support — may eventually automate frailty identification using information already available in the medical record, reducing the burden on clinicians while improving consistency.

Frailty Should Change the Care Plan

“Frailty should fundamentally change how clinicians estimate risk, rather than automatically changing which treatments are offered,” Verebes said. “Frail patients are substantially more vulnerable to complications including delirium, falls, medication-related adverse events, pressure injuries, prolonged hospitalization, functional decline, institutionalization, and mortality.”

Recognizing frailty encourages clinicians to look beyond the admitting diagnosis, she said, and consider factors such as a patient’s baseline mobility, recent functional decline, caregiver support, and anticipated discharge needs. Frailty also should guide discussions about prognosis and goals of care, ensuring that treatment plans align with a patient’s priorities, expected recovery, and quality of life rather than the acute illness alone.

Ulin said hospitalists often recognize frailty but do not consistently assess or document it.

“For many frail patients, hospitalizations aren’t isolated events — each hospitalization can result in cumulative losses in physiologic reserve, making recovery from the next illness even more difficult,” she said. “Frailty may not be why someone is admitted to the hospital — but it should change how we care for them.”

Earlier Multidisciplinary Care Can Help Preserve Function

Frailty should prompt multidisciplinary involvement early in a patient’s hospitalization rather than after complications have already developed, Verebes said.

“Physical therapy consultation should occur within the first 24-48 hours whenever patients demonstrate mobility decline, generalized weakness, impaired balance, recurrent falls, prolonged bed rest, or decreased endurance,” she said. “Physical therapists are uniquely positioned to identify early frailty-associated impairments, including slowed gait speed, weakness, fatigue, and declining functional independence, allowing rehabilitation to begin before significant deconditioning occurs.”

She said nutritional assessment also should be considered for patients with unintentional weight loss, sarcopenia, reduced oral intake, or protein-calorie malnutrition, while pharmacy consultation can help identify medications that contribute to dizziness, orthostatic hypotension, falls, sedation, and impaired mobility. Medication reconciliation and deprescribing can substantially reduce those risks, she said.

Ulin said palliative care also has an important role in caring for frail patients.

“In palliative care, we often see the downstream consequences of frailty. We see how a single hospitalization can significantly alter a patient’s functional trajectory — and a caregiver’s ability to continue supporting them at home. These difficult experiences reinforce why recognizing frailty early matters,” she said.

Patients with advanced frailty, recurrent hospitalizations, uncertain prognoses, or complex decision-making needs may also benefit from earlier palliative care involvement to support symptom management and goals-of-care discussions, Verebes said.

Case Study: When Frailty Changes the Discharge Plan

Verebes cared for one patient, Mrs J., an 84-year-old woman admitted with community-acquired pneumonia who appeared medically ready for discharge after 3 days of intravenous antibiotics. However, frailty screening identified recent weight loss, persistent fatigue, slowed gait, and declining physical activity.

Physical therapy found impaired balance and decreased lower-extremity strength, nutrition identified protein-calorie malnutrition, and pharmacy determined that several antihypertensive medications were contributing to orthostatic hypotension. Instead of being discharged directly home, the interdisciplinary team arranged rehabilitation to address her functional decline and reduce her risk for falls and readmission.

Although Mrs. J.’s pneumonia had resolved, her diminished physiologic reserve and functional decline placed her at significant risk for falls, readmission, and loss of independence. Verebes said the case illustrates how frailty assessment can change clinical management by prompting earlier rehabilitation, medication optimization, and more individualized discharge planning.

Mobility and Function Should Matter Too

Traditional hospital quality metrics focus on mortality, length of stay, complications, and readmissions, but experts said those measures don’t fully capture the outcomes that matter most to patients.

“Mobility and functional status should be considered essential quality measures in hospital medicine because they reflect outcomes that matter most to patients,” Verebes said. “Traditional hospital quality metrics emphasize mortality, readmissions, complications, and length of stay, yet these measures provide little insight into whether patients retain the ability to walk, transfer independently, perform activities of daily living, or safely return home.”

She said routine documentation of baseline mobility, mobility during hospitalization, and functional status at discharge would help shift hospital care toward more patient-centered outcomes.

Ulin agreed.

“Patients often measure success by whether they’ll be able to walk back into their own home and care for themselves,” she said. “If we want to provide patient-centered care, mobility and functional status deserve recognition as core quality measures. If we’re reporting falls, we should also measure whether we did the things most likely to prevent them.”

As hospitals care for an increasingly older and more medically complex patient population, experts said recognizing frailty may become less about adding another screening requirement and more about ensuring that treatment plans, rehabilitation efforts, and discharge planning are aligned with each patient’s physiologic reserve and functional goals.

The experts cited in this article reported no relevant disclosures.