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.

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.

Figures