External Validation of the ISAN, A2DS2, and AIS-APS Scores for Predicting Stroke-Associated Pneumonia

The Prestroke Independence, Sex, Age, National Institutes of Health Stroke Scale (ISAN), Age, Atrial Fibrillation, Dysphagia, male sex, and National Institutes of Health Stroke Scale (A2DS2), and acute ischemic stroke-associated pneumonia score (AIS-APS) scores were created to predict stroke-associated pneumonia (SAP), one of the most important medical stroke complications. External validation of all such scores in an acute stroke population was the aim of our study.

Patients with ischemic or hemorrhagic stroke were prospectively enrolled in the multicenter Stroke-Induced Pneumonia in Andalucía project between October 2014 and May 2016. Receiver operating characteristic curves and linear regression analyses were used to determine discrimination ability of the scores. The Hosmer-Lemeshow goodness-of-fit test and the plot of observed versus predicted SAP risk were used to assess model calibration.

Among 201 included patients, SAP rate was 15.5% (31). Higher ISAN, A2DS2, and AIS-APS scores were related to SAP (all P < .001). The C statistic was .83 (95% confidence interval [CI], .76-.91) for the ISAN score, .80 (95% CI, .70-.89) for the A2DS2 score, and .82 (95% CI, .74-.90) for the AIS-APS score, suggesting good discrimination. The ISAN and AIS-APS scores showed good calibration (Cox and Snell R² = .206 and .174, respectively). The A2DS2 score showed the highest sensitivity (87%), and the AIS-APS score showed the highest specificity (92.8%).

In our cohort, the external validation of ISAN, A2DS2, and AIS-APS scores have demonstrated their accurate prediction of SAP and the ability of these scores as screening tools to better manage SAP. The AIS-APS score would be recommendable for the development of future clinical trials.