Pneumonia is one of the leading causes of infection-related mortality in the older population. Traditional severity scores used in emergency departments, such as the Pneumonia Severity Index (PSI) and CURB-65, primarily focus on acute physiological derangements and may not adequately capture biological reserve and frailty in older adults. Frailty is a geriatric syndrome reflecting increased vulnerability to stressors and reduced recovery capacity.

This prospective observational cohort study aims to evaluate the predictive value of the Clinical Frailty Scale (CFS) for in-hospital mortality, 30-day mortality, and morbidity in patients aged 65 years and older presenting to the emergency department with pneumonia. Additionally, the study will assess whether incorporating frailty assessment into existing pneumonia severity scores improves prognostic accuracy.

Pneumonia represents a major cause of hospitalization, intensive care admission, and mortality in older adults worldwide. Aging is associated with multimorbidity and immunosenescence, increasing vulnerability to infection and poor outcomes. Current risk stratification tools used in emergency departments, including PSI and CURB-65, are designed to estimate short-term mortality based on acute clinical variables. However, these tools may not fully reflect functional reserve and biological age.

Frailty is characterized by decreased physiological reserve and increased susceptibility to adverse outcomes. The Clinical Frailty Scale (CFS), based on the deficit accumulation model, provides a rapid bedside assessment of global functional status using a 9-point scale. Emerging evidence suggests that frailty is an independent predictor of mortality and morbidity in older emergency department populations.

This single-center prospective observational cohort study will be conducted in a tertiary university hospital emergency department. Patients aged ≥65 years with a clinical and radiological diagnosis of pneumonia will be enrolled consecutively. Demographic data, comorbidities, vital signs, and PSI scores will be recorded at presentation. Frailty will be assessed using the Clinical Frailty Scale at the bedside.

The primary outcomes are in-hospital mortality and 30-day mortality. Secondary outcomes include intensive care unit admission and need for mechanical ventilation. Statistical analysis will evaluate whether CFS independently predicts outcomes and whether adding frailty assessment to existing pneumonia severity scores improves prognostic performance.

Inclusion Criteria:

• Age ≥65 years
• Clinical and radiological diagnosis of pneumonia in the emergency department
• Ability to obtain informed consent from the patient or legal representative
• Availability of a caregiver or relative able to describe baseline functional status

Exclusion Criteria:

• Presentation with cardiopulmonary arrest or ongoing cardiopulmonary resuscitation at admission
• Confirmed COVID-19 pneumonia
• Inability to obtain reliable baseline functional history due to absence of an informant
• Refusal to provide informed consent

Older adults aged 65 years and above presenting to a tertiary university hospital emergency department with a clinical and radiological diagnosis of pneumonia. The study population represents geriatric patients with acute infectious respiratory illness requiring emergency evaluation, including a wide range of comorbidity and functional status levels typical of real-world emergency department practice.