Frailty on in-hospital death in older patients with acute exacerbation of chronic obstructive pulmonary disease: a real-world prospective cohort study

BACKGROUND Few evidence exists for the effect of frailty on the patients admitted with an acute exacerbation of chronic obstructive pulmonary disease (AECOPD). OBJECTIVE We explored the link of frailty and in-hospital death, and whether laboratory indicators mediate this association. METHODS This was a real-world prospective cohort study including older patients with AECOPD, consisting of two cohorts, training set (n=1356) and validation set (n=478). The independent prognostic factors including frail status were determined by multivariate logistic regression analysis. The relationship between frailty and in-hospital mortality was estimated by multivariable Cox regression. A nomogram was developed to provide the clinician with a quantitative tool to predict the risk of in-hospital death. Mediation analyses for frailty and in-hospital death were conducted. RESULTS The training set included 1356 patients(aged 86.7±6.6), and 25.0% of them were frail. A nomogram model was created, including ten independent variables: age, sex, frailty, chronic obstructive pulmonary disease grades (COPD grades), severity of exacerbation, mean arterial pressure (MAP), Charlson Comorbidity Index (CCI), Interleukin-6 (IL-6), albumin, and troponin T (TPN-T). The area under the receiver operating characteristic curve (ROCs) was 0.862 and 0.845 for the training set and validation set, respectively. Patients with frailty had higher risk of in-hospital death than those without frailty (HR,1.83, 95%CI: 1.14-2.94; p=0.013). Furthermore, CRP and albumin mediated the associations between frailty with in-hospital death. CONCLUSIONS Frailty may be an adverse prognostic factor for older patients admitted with an AECOPD. CRP and albumin may be parts of the immunoinflammatory mechanism between frailty and in-hospital death.