Acute exacerbation of Interstitial Lung Disease specific comorbidity Index (AEILD-CI) to assess the risk of in-hospital death: a prospective cohort study

Few information on how comorbidities should be identified and assessed in AE-ILD patients existed. A practically clinical tool based on comorbidities is needed. To identify the comorbidities and develop an AEILD-CI, a prospective cohort with AE-ILD inpatients were conducted. Comorbidity diagnoses and assessment were based on standardised definitions. In the training set of 3468 patients, univariate analysis compared the risk of in-hospital outcomes associated with individual comorbidities, comorbidity systems, and numbers of comorbidities. The AEILD-CI was developed by LASSO-logistic regression and validated in external validation set of 1565 patients. We stratified patients into three risk groups and tested in-hospital outcomes between subgroups. Seventeen of the 63 comorbidities differed in the prevalence between 3254 survivors and 214 non-survivors. 82.1% patients had multiple (≥2) comorbidity systems. The AEILD-CI included eleven comorbidities with 0.84 C-statistic, and overall risk ratio for death conferred by a one-point increase was 1.60 (95%CI:1.52-1.69). The high-risk comorbidity group (AEILD-CI≥5) increased by 9.8-fold the risk of death. Comorbidities are frequent in AE-ILD patients and associated with poor prognosis. Most patients have a “comorbidity system overlap”. AEILD-CI can be calculated at: https://dlryvs-zhao-cy.shinyapps.io/ILDapp/. <fig><object-id>erj;64/suppl_68/PA679/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>