Development and validation of a clinical-friendly model for predicting 180-day mortality in the older with...

Currently, there is no effective way to identify older patients with community-acquired pneumonia (CAP) at high risk of long-term death. We aimed to develop and validate a pneumonia scoring system to predict 180-day mortality, and compare its performance with the commonly used CURB-65 score.

The prospective cohort study enrolled patients aged 65 years and older with CAP from 10 medical centers in China between April 2021 and December 2023. The primary outcome was 180-day mortality. A Cox proportional hazards model was used to develop a new pneumonia scoring system, and the area under the time-dependent curve (AUC) was used to assess its discriminatory power. Internal validation was performed using both bootstrap resampling and 10-fold cross-validation. The model was visualized by a nomogram and a questionnaire. The optimal cutoff value of the nomogram was determined based on the maximum Youden index for the 180-day mortality prediction, dividing patients into high- and low-risk groups. The performance of model in predicting both short- and long-term mortality was compared with CURB-65 using AUC, sensitivity, specificity, negative predictive value and positive predictive value.

A total of 619 patients, with a median age of 78 years (IQR: 70.5-85.0), were included in the analysis. The 180-day mortality was 6.9%. The model was developed using six variables, including age, the ratio of pulse oximetry saturation (SpO₂) to the fraction of inspired oxygen (FiO₂), loneliness, Barthel index, Clinical Frailty Scale and malnutrition. The AUC of the model for predicting 180-day, 90-day and 30-day mortality were 0.829, 0.832 and 0.904, respectively. The cut-off value for the model was 142, while it was 2 for CURB-65. Using the cut-off values, the AUC of the model for predicting 180-day mortality was 0.768 (95% confidence interval [CI]: 0.695-0.842), significantly higher than that of CURB-65(AUC: 0.573, 95%CI: 0.488-0.659). A similar trend was observed for predictions of 90-day, 30-day and in-hospital mortality.

This study developed and validated a prediction model for long-term mortality in older patients with CAP, showing better discriminatory power and accuracy over CURB-65.