RESUMO
Objective By now, there is no unified definition of aspiration pneumonia. However, patients with community-acquired pneumonia (CAP) often have aspiration risk factors. The aims of our study is to explore the clinical characteristics and outcomes of CAP patients with aspiration risk factors. Methods Cases data of all patients hospitalized with CAP in 5 teaching hospitals in Beijing, Shandong Province and Yunnan Province from January 1, 2013 to December 31, 2015 were collected. Data from patients with (AR-CAP) and without (non AR-CAP) aspiration risk factors were compared, including demographic features, clinical and radiologic findings and outcomes. A Cox proportional hazard model was used to determine the impact of aspiration risk factors on the 30-day mortality in CAP patients. Receiver operating characteristic curves (ROCs) was performed to verify the accuracy of CURB-65 score and PSI risk classification as 30-day mortality predictors in AR-CAP patients. Results Totally, 3561 CAP cases were entered into the final analysis. AR-CAP cases accounted for 5.1% (180/3561), who showed older age [78.0 yrs (M1,M3: 70.0 yrs, 85.0 yrs) vs 63.0 yrs (M1,M3: 52.0 yrs, 77.0 yrs), P < 0.001), more underlying diseases (91.1% vs 71.3%, P < 0.001), more frequently classified as CURB-65 score ≥ 3 (13.3% vs 1.5%, P < 0.001) and PSI risk classification ≥ Ⅳ (53.7% vs 17.0%，P< 0.001), and higher 30-day mortality (10.0% vs 1.8%, P < 0.001). Adjusted for age, sex, comorbidities and CURB-65/PSI score, aspiration risk factors were associated with increased 30-day mortality of CAP patients (HR 2.844, 95% CI 1.331~6.078, P = 0.007). The area under the ROC curve for predicting 30-day mortality in AR-CAP patients by PSI risk class was 0.716, which was higher than CURB-65 score (AUC=0.518, P = 0.019). The difference was statistically significant. Conclusion AR-CAP is a distinctive pneumonia phenotype with unique clinical characteristics, which shows more illness severity and worsen outcomes.