The relationship between the Barthel Index and stroke-associated pneumonia in elderly patients and factors of SAP

Abstract Background Stroke-associated pneumonia (SAP) is a common complication in stroke patients, and the Barthel Index (BI) is a well-established metric for assessing activities of daily living (ADL). However, the association between BI and SAP in acute ischemic stroke (AIS) patients remains unclear. This study aims to investigate the relationship between BI at admission and SAP, and explore the factors in AIS elderly patients. Method Retrospective data were collected from ischemic stroke patients hospitalized at the Second Affiliated Hospital of Nanchang University between January 2018 and July 2021, including their basic demographic and laboratory test results. Restricted cubic spline regression, multivariate logistic regression analysis, and receiver operating characteristic (ROC) curve analysis were employed to investigate the relationship between BI and SAP. Additionally, the Shapley Additive exPlanations (SHAP) method was used to identify the factors influencing SAP. Results The study included 7,548 eligible stroke patients with a mean age of 75.1 ± 7.6 years, among which 41.14% were female. The SAP group demonstrated significantly lower BI compared to the non-SAP group (50.86 ± 35.60 vs. 75.27 ± 26.33, P