Predictive value of the Elixhauser comorbidity index in assessing the risk of coronavirus disease (COVID-19) mortality in patients with pneumonia

Aim. To determine the spectrum of comorbid pathology and to find out the prognostic value of the Elixhauser Comorbidity Index (ECI) in assessing the risk of death from coronavirus disease (COVID-19) in patients with pneumonia. Material and methods. The study included 123 patients with COVID-19 with pneumonia who were examined and treated according to the Order of the Ministry of Health of Ukraine of 28.03.2020 No. 722. Depending on the disease outcome, the patients were divided into groups: 77 patients who recovered and 46 patients who died. The ECI was calculated for all the patients. Statistical processing of the data was performed using Statistica for Windows 13 (StatSoft Inc., No. JPZ804I382130ARCN10-J). Results. In patients with COVID-19 and pneumonia, comorbid conditions were most often represented by chronic cardiovascular disease (63.4 %), obesity (28.5 %), endocrine pathology (26.0 %) and discirculatory encephalopathy (23.6 %). Among patients with a fatal outcome, coronary heart disease with cardiac arrhythmias, obesity, endocrine diseases, primarily diabetes mellitus, and discirculatory encephalopathy were more common (p < 0.05) as compared to patients who recovered. Among the comorbidities integrated into the ECI, the most commonly diagnosed comorbidities in COVID-19 patients with pneumonia were hypertension (58.5 %), congestive heart failure (33.3 %), obesity (28.5 %), neurodegenerative disorders (23.6 %), and diabetes, both without (13.8 %) and with chronic complications (7.7 %). The following ECI components were more common in patients with COVID-19 pneumonia who died as a result of COVID-19 than in patients who recovered: congestive heart failure (p = 0.008), cardiac arrhythmias (p = 0.001), neurodegenerative disorders (p = 0.0003), diabetes mellitus (p = 0.004) including diabetes without chronic complications (p = 0.01), and obesity (p = 0.04). The ECI score in patients with a fatal outcome was 2.2 times higher (p < 0.05) than that in patients with COVID-19 pneumonia who recovered. The ECI >7 was predictive of the likelihood of COVID-19 death in patients with pneumonia (AUC = 0.656, p = 0.002). Conclusions. The frequency of chronic comorbidities in patients with COVID-19 and pneumonia has been determined taking into account the ECI components. The prognostic significance of the ECI score >7 in assessing the risk of fatal outcome has been established.