Frailty score predicts outcomes in Australian pneumonia patients, study finds

Older people hospitalised with community-acquired pneumonia who score higher on a simple administrative frailty measure tend to stay in hospital longer, need intensive care more often, and are more likely to die, according to a retrospective observational study conducted at two Australian hospitals.

The study, published in the journal Aging Clinical and Experimental Research, set out to externally validate the Hospital Frailty Risk Score (HFRS) in an Australian population of patients admitted with community-acquired pneumonia, a condition that is common globally and disproportionately affects older, frailer people. The HFRS assesses frailty using routinely collected administrative data, but its performance in evaluating clinical outcomes among hospitalised Australian pneumonia patients had not previously been assessed.

The researchers examined all adult emergency admissions for community-acquired pneumonia between 1 January 2018 and 31 December 2023 at two Australian hospitals. Data were captured from electronic medical records using the International Classification of Diseases. Patients were classified as non-frail if their HFRS was below 5 and as frail if the score was 5 or above.

The cohort comprised 6,885 patients with a mean age of 75.4 years (standard deviation 17.4), and 54.7 percent were male. The mean HFRS was 5.3 (standard deviation 4.8), and 41.7 percent of patients were classified as frail.

Using multilevel multivariable regression analysis, the team tested whether the score predicted a range of clinical outcomes: length of hospital stay, risk of intensive care unit admission, in-hospital mortality, 30-day and 365-day mortality, and 30-day readmission risk.

Each increasing point on the HFRS significantly predicted a longer hospital stay, with an incidence rate ratio of 1.07, and a greater likelihood of ICU admission, with an adjusted odds ratio of 1.12. Higher scores were also associated with higher in-hospital mortality (adjusted odds ratio 1.06), higher 30-day mortality (adjusted odds ratio 1.05) and higher 365-day mortality (adjusted odds ratio 1.02), with p values of 0.001 or less for all of these outcomes.

By contrast, the HFRS was not significantly associated with the risk of readmission within 30 days of discharge, indicating that the score’s predictive value in this cohort was limited to the in-hospital and early and longer-term mortality outcomes and to resource use measures such as length of stay and ICU admission.

The authors conclude that the HFRS is a practical, low-cost tool which could have far-reaching implications for streamlining clinical care worldwide, and that the evidence for its use is becoming more robust with each subsequent validation study. As a retrospective observational analysis of administrative data from two hospitals, the study establishes associations between the score and outcomes in this population rather than demonstrating that the score itself changes care, and the findings apply to the Australian pneumonia cohort studied. The work adds Australian evidence to a growing body of validation studies of the score, which has previously been examined in other settings, including critically ill patients and older adults receiving mechanical ventilation.

Subject of Research: External validation of the Hospital Frailty Risk Score for predicting clinical outcomes in patients hospitalised with community-acquired pneumonia in Australia

Article Title: External validation of the hospital frailty risk score for predicting clinical outcomes in patients hospitalised with community acquired pneumonia in two Australian hospitals

Article References: Hauser, M., Mangoni, A. A., Thompson, C., Horwood, C., & Sharma, Y. (2026). External validation of the hospital frailty risk score for predicting clinical outcomes in patients hospitalised with community acquired pneumonia in two Australian hospitals. Aging Clinical and Experimental Research. https://doi.org/10.1007/s40520-026-03518-w

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DOI: 10.1007/s40520-026-03518-w

Keywords: frailty, Hospital Frailty Risk Score, community-acquired pneumonia, hospitalisation, mortality, length of stay, ICU admission, risk stratification, older adults, retrospective study, Australia, External