Establishment of risk prediction model and risk score for in-hospital mortality in patients with AECOPD

Objective Risk stratification for patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) may help clinicians choose appropriate treatments and improve the quality of care. Methods A total of 695 patients hospitalized with AECOPD from January 2015 to December 2017 were considered. They were assigned to a death and a survival cohort. The independent prognostic factors were determined by multivariate logistic regression analysis. Meanwhile, we also compared the new scale with three other scores and tested the new scale internally and externally. Results A new risk score was created, made up of six independent variables: age, D-dimer, albumin, cardiac troponin I, partial pressure of carbon dioxide and oxygenation index. The area under the receiver operator characteristic curve (AUROC) for the model was 0.929, and the other three CURB-65, DECAF and BAP-65 models were 0.718, 0.922 and 0.708. The Cohen's kappa coefficient between the new scale and DECAF was calculated to be 0.648, suggesting that there is a substantial consistency between the two. In the internal and external validation cohorts, 490 and 500 patients were recruited with a total mortality rate of 5.15%. The AUROC for in-hospital mortality was 0.937 in the internal cohort and 0.914 in external cohort, which was significantly better than the scores for CURB-65 and BAP-65, but it was not significantly different from the DECAF. Conclusions The new scale may help to stratify the risk of in-hospital mortality of AECOPD. The DECAF performed as well as the new instrument, and it appears to be valid in Chinese patients.