Evaluating the predictive performance of PIRO score against six clinical prediction scores for COVID-19 outcomes in the emergency department

Abstract

The coronavirus disease 2019 (COVID-19) pandemic has led to the development of numerous prognostic models for patient assessment. However, the potential utility of the predisposition, insult/infection, response, organ dysfunction (PIRO) score in evaluating COVID-19 severity and outcomes remains unexplored, presenting a gap in current research. A retrospective analysis was conducted on a cohort of 374 individuals diagnosed with COVID-19 who were admitted to the emergency department of Beijing Youan Hospital. Demographic data, treatment regimens, and seven prognostic scoring systems, including PIRO, were evaluated. To evaluate the models' prognostic accuracy for 28-day mortality, area under the receiver operating characteristic (AUROC) analysis was employed. Comparative performance between scoring systems was quantified using the DeLong method for paired ROC curves. Of the 374 patients meeting inclusion criteria, 120 (32.1%) died within 28 day of hospitalization. Significant disparities were observed between survivors and non-survivors regarding age, laboratory parameters, and clinical scores. Analysis of patient distribution and mortality rates across different score ranges revealed a positive correlation between score magnitude and 28-day mortality. The PIRO score demonstrated superior prognostic capability, yielding an AUC of 0.898 (95% CI 0.866-0.929). The quick sequential organ failure assessment (qSOFA) score followed closely (AUC 0.882, 95% CI 0.849-0.914). Both critical illness risk score (COVID-GRAM) and national early warning score 2 (NEWS2) exhibited AUCs exceeding 0.85 (COVID-GRAM 0.854, 95% CI 0.812-0.895; NEWS2: 0.851, 95% CI 0.813-0.889). DeLong test analysis revealed statistically significant differences in AUC between PIRO and confusion, urea, respiration, systolic pressure, age ≥ 65 (CURB-65), pneumonia severity index (PSI), COVID-GRAM, rapid acute physiology score (RAPS), and NEWS2 (all p < 0.05). Analysis revealed the PIRO scoring system as a robust predictor of 28-day mortality among COVID-19 cases presenting to the emergency setting, offering potential refinement of risk stratification and clinical management strategies.

Keywords: 28-day mortality; COVID-19; Clinical scoring system; Emergency department; PIRO score.

Fig. 1

Flow diagram of patients enrollment.

Fig. 2

Distribution of 28-day survival and mortality in patients based on the PIRO score. Frequency distribution plot (A), where each group represents a score of 3 and is stacked to visualize the distribution of patients with different scores. Stacked bar chart (B), showing the proportions of 28-day survivors and deceased individuals in different PIRO score groups. PIRO, predisposition, insult/infection, response, organ dysfunction.

Fig. 3

Frequency distribution plots of 28-day survival and mortality in patients based on six clinical prediction scores. According to qSOFA (A), CURB-65 (B), PSI (C), COVID-GRAM (D), RAPS (E), and NEWS2 (F). The plots illustrate the distribution of patients with different scores. For PSI (C), each group represents a score of 30 and is stacked sequentially. For COVID-GRAM, the first group represents scores from 41 to 80, with each subsequent group incremented by 40 and stacked accordingly. qSOFA, quick sequential organ failure assessment; CURB-65: confusion, urea, respiration, systolic pressure, age ≥ 65; PSI, pneumonia severity index; RAPS: rapid acute physiology score; NEWS2, national early warning score 2.

Fig. 4

Stacked bar charts depicting the proportions of 28-day survivors and deceased individuals in different score groups based on six clinical prediction scores. According to qSOFA (A), CURB-65 (B), PSI (C), COVID-GRAM (D), RAPS (E), and NEWS2 (F). The charts provide insights into the distribution of survivors and deceased individuals in different score categories. qSOFA, quick sequential organ failure assessment; CURB-65, confusion, urea, respiration, systolic pressure, age ≥ 65; PSI, pneumonia severity index; RAPS, rapid acute physiology score; NEWS2, national early warning score 2.

Fig. 5

Prediction of 28-day mortality in COVID-19 patients using seven clinical prediction scores. Receiver Operating Characteristic (ROC) curves (A). The area under the curve (AUC) for qSOFA was 0.882 (95% confidence interval [CI] 0.849–0.914); CURB-65, AUC was 0.843 (95% CI 0.802–0.884); PIRO, AUC was 0.898 (95% CI 0.866–0.929); COVID-GREM, 0.854 (95% CI 0.812–0.895); PSI, AUC was 0.804 (95% CI 0.757–0.854); RAPS, AUC was 0.835 (95% CI 0.790–0.879); NEWS2, AUC was 0.851 (95% CI 0.813–0.889. Decision curve analysis (B). A box plot of the AUC distribution for 10-fold cross-validation of different scoring systems (C). A bar chart of Brier scores for predicting mortality using different scoring systems (D). PIRO, predisposition, insult/infection, response, organ dysfunction; qSOFA, quick sequential organ failure assessment; CURB-65, confusion, urea, respiration, systolic pressure, age ≥ 65; PSI, pneumonia severity index; RAPS, rapid acute physiology score; NEWS2, national early warning score 2.