# Frailty as a Key Determinant of In-Hospital Mortality in 58,040 Patients with Community-Acquired Pneumonia: Evidence from a Chilean Cohort

## TL;DR

This study shows that frailty is a major factor in predicting hospital deaths from pneumonia in older adults in Chile.

## Contribution

The study provides new evidence from Latin America on the role of frailty in predicting mortality in older pneumonia patients.

## Key findings

- Frailty was a strong independent predictor of in-hospital mortality in older adults with pneumonia.
- Advanced age, male sex, and higher DRG severity were also significant mortality predictors.
- Comorbidity burden lost significance after adjusting for other factors.

## Abstract

Background: Pneumonia is a leading cause of hospitalization and death among older adults, reflecting both patient vulnerability and the quality of acute care. However, evidence from Latin America remains limited. Objective: to examine the association between frailty level assessed using the HFRS and in-hospital mortality among older adults hospitalized with community-acquired pneumonia (CAP). Methods: We conducted a retrospective cohort study using the Chilean National Health Fund (Fondo Nacional de Salud, FONASA) database, including patients aged ≥ 60 years hospitalized with CAP (ICD-10 codes J12–J18) between 2019 and 2024. Variables analyzed included age, sex, frailty level assessed by the Hospital Frailty Risk Score (HFRS), comorbidity burden (Charlson Comorbidity Index), Diagnosis-Related Group (DRG) severity level, and relative weight. Survival was analyzed using Kaplan–Meier curves and log-rank tests. Multivariable Cox proportional hazards models estimated adjusted hazard ratios (HR) with 95% confidence intervals (CI). Results: The cohort comprised 58,040 patients (51.2% women). Overall, in-hospital mortality was 19.3%. Independent predictors of mortality included advanced age (≥90 years: HR = 2.41; 95% CI: 2.27–2.56), male sex (HR = 1.10; 95% CI: 1.06–1.14), high frailty risk (HR = 1.57; 95% CI: 1.47–1.68), and greater DRG severity (per level: HR = 1.66; 95% CI: 1.58–1.73). The Charlson Comorbidity Index lost significance after adjustment. Conclusions: Frailty emerged as a strong and independent determinant of in-hospital mortality in older adults with CAP. Systematic frailty assessment combined with comorbidity indices could improve risk stratification and guide more personalized, evidence-based clinical management in acute care settings.