Can the ADO Index Be Used as a Predictor of Mortality from COVID-19 in Patients with COPD?

Esra Ertan Yazar,1 Gulsah Gunluoglu,2 Burcu Arpinar Yigitbas,1 Mukadder Calikoglu,3 Gazi Gulbas,4 Nilgün Y&inodot;lmaz Demirci,5 Nurhan Sarioglu,6 Fulsen Bozkus,7 Nevin Taci Hoca,5 Nalan Ogan,8 Seda Tural Onur,2 Muzaffer Onur Turan,9 Filiz Kosar,2 Evrim Eylem Akpinar,8 Burak Mete,10 Can Ozturk5 1Department of Chest Diseases, Istanbul Medeniyet University, Medical Faculty, Istanbul, Turkey; 2Department of Chest Diseases, Yedikule Chest Disease and Chest Surgery Research and Training Hospital, Istanbul, Turkey; 3Department of Chest Diseases, Mersin University, Medical Faculty, Mersin, Turkey; 4Department of Chest Diseases, Inonu University, Medical Faculty, Malatya, Turkey; 5Department of Chest Diseases, Gazi University, Medical Faculty, Ankara, Turkey; 6Department of Chest Diseases, Balikesir University, Medical Faculty, Balikesir, Turkey; 7Department of Chest Diseases, Kahramanmaras Sutcu Imam University, Medical Faculty, Kahramanmaras, Turkey; 8Department of Chest Diseases, Ufuk University, Medical Faculty, Ankara, Turkey; 9Department of Chest Diseases, Prof Dr, Izmir Katip Celebi University, Atatürk Research and Training Hospital, Izmir, Turkey; 10Department of Public Health Çukurova University, Medical Faculty, Adana, TurkeyCorrespondence: Esra Ertan Yazar, Istanbul Medeniyet University, Medical Faculty, Department of Chest Diseases, Istanbul, Turkey, Email [email protected]: Several studies have shown that the risk of mortality due to COVID-19 is high in patients with COPD. However, evidence on factors predicting mortality is limited.Research Question: Are there any useful markers to predict mortality in COVID-19 patients with COPD?.Study Design and Methods: A total of 689 patients were included in this study from the COPET study, a national multicenter observational study investigating COPD phenotypes consisting of patients who were followed up with a spirometry-confirmed COPD diagnosis. Patients were also retrospectively examined in terms of COVID-19 and their outcomes.Results: Among the study patients, 105 were diagnosed with PCR-positive COVID-19, and 19 of them died. Body mass index (p= 0.01) and ADO (age, dyspnoea, airflow obstruction) index (p= 0.01) were higher, whereas predicted FEV1 (p< 0.001) and eosinophil count (p= 0.003) were lower in patients who died of COVID-19. Each 0.755 unit increase in the ADO index increased the risk of death by 2.12 times, and each 0.007 unit increase in the eosinophil count decreased the risk of death by 1.007 times. The optimum cut-off ADO score of 3.5 was diagnostic with 94% sensitivity and 40% specificity in predicting mortality.Interpretation: Our study suggested that the ADO index recorded in the stable period in patients with COPD makes a modest contribution to the prediction of mortality due to COVID-19. Further studies are needed to validate the use of the ADO index in estimating mortality in both COVID-19 and other viral respiratory infections in patients with COPD.Keywords: body mass index, COVID-19, eosinophils, FEV1, mortality, pneumonia, pulmonary disease, chronic obstructiv