Development of a new prognostic model to predict pneumonia outcome using artificial intelligence-based chest radiograph results

Abstract

This study aimed to develop a new simple and effective prognostic model using artificial intelligence (AI)-based chest radiograph (CXR) results to predict the outcomes of pneumonia. Patients aged > 18 years, admitted the treatment of pneumonia between March 2020 and August 2021 were included. We developed prognostic models, including an AI-based consolidation score in addition to the conventional CURB-65 (confusion, urea, respiratory rate, blood pressure, and age ≥ 65) and pneumonia severity index (PSI) for predicting pneumonia outcomes, defined as 30-day mortality during admission. A total of 489 patients, including 310 and 179 patients in training and test sets, were included. In the training set, the AI-based consolidation score on CXR was a significant variable for predicting the outcome (hazard ratio 1.016, 95% confidence interval [CI] 1.001-1.031). The model that combined CURB-65, initial O₂ requirement, intubation, and the AI-based consolidation score showed a significantly high C-index of 0.692 (95% CI 0.628-0.757) compared to other models. In the test set, this model also demonstrated a significantly high C-index of 0.726 (95% CI 0.644-0.809) compared to the conventional CURB-65 and PSI (p < 0.001 and 0.017, respectively). Therefore, a new prognostic model incorporating AI-based CXR results along with traditional pneumonia severity score could be a simple and useful tool for predicting pneumonia outcomes in clinical practice.

Keywords: Artificial intelligence; Mortality; Pneumonia; Prognosis; Radiography.

Figure 1

Flowchart of patient inclusion.

Figure 2

The calibration plot of model D. The calibration plot of model D for test set showed a relatively good fit to the 45-degree line.

Figure 3

Example cases of patients with pneumonia. (a) A patient with a CURB-65 of 2 and PSI of 97 had an initial O₂ requirement of 6L, no intubation, and an AI-based consolidation score of 96% on the initial CXR. This patient died during admission for pneumonia treatment. (b) A patient with a CURB-65 of 1 and PSI of 117 had an initial O₂ requirement of 2L, no intubation, and a consolidation score of 40% on the initial CXR. This patient recovered and was discharged after treatment. CURB-65, confusion, urea, respiratory rate, blood pressure, and age ≥ 65; CXR, chest radiograph; PSI, pneumonia severity index; Csn, consolidation.