Predictive value of C-reactive protein-to-albumin ratio for risk of 28-day mortality in patients with severe pneumonia

Objectives: To explore the predictive value of C-reactive protein (CRP)-to-albumin (ALB) ratio (CAR) for the risk of 28-day mortality in patients with severe pneumonia.Methods: A total of 152 patients with severe pneumonia treated from January 2020 to January 2022 were enrolled and assigned into survival group (n=107) and death group (n=45) according to their survival status after treatment for 28 d. Their clinical data were compared, and the influencing factors for 28-day mortality were explored by multiple logistic regression analysis. The receiver operating characteristic (ROC) curve was plotted to assess the value of CAR for predicting 28-day mortality risk. A risk prediction model was constructed, and its prediction efficiency was evaluated.Results: The death group had significantly older age, Acute Physiology and Chronic Health Evaluation (APACHE) II score, Murray Lung Injury Score, Sequential Organ Failure Assessment score, white blood cell count, neutrophil count, red cell volume distribution width, neutrophil-to-lymphocyte ratio (NLR), fibrinogen, procalcitonin, blood lactic acid (Lac), CRP and CAR and significantly lower oxygenation index and ALB than those of the survival group (p<0.05). APACHE II score, NLR, Lac and CAR were independent risk factors for 28-day mortality (p<0.05). AUC of the established prediction model was 0.826, with sensitivity of 88.45 % and specificity of 87.32 %, indicating high discrimination. The nomogram model had clinical value when the risk threshold probability was 11-93 %.Conclusions: CAR is an independent risk factor that shows a high predictive value for the 28-day mortality risk in patients with severe pneumonia.