ABSTRACT
Background: Considering the role of higher blood urea nitrogen and lower serum albumin (SA) levels in deceased COVID-19 patients, increased blood urea nitrogen to SA (B/A) ratio may help to determine those at higher risk of becoming critically ill. This study evaluated the association of SA level and B/A ratio with disease severity and 30–day mortality and also their predictive value for disease severity in COVID–19 patients. Methods: 433 adult patients with COVID–19, admitted to a referral medical center in Tehran, Iran, from February to May 2020 were included. The laboratory markers were measured on admission. Disease severity was categorized into mild disease, severe pneumonia, acute respiratory distress syndrome (ARDS), sepsis, and septic shock. The mortality was followed up for thirty days after admission. Results: Thirty–day mortality rate was 27.25%. The frequency of mild, severe pneumonia, ARDS, sepsis, and septic shock was 30.72%, 36.95%, 24.02%, 6.00%, and 2.31%, respectively. Mean B/A ratio was different among different disease severities. The odds of thirty-day mortality increased by 16% by each unit increase in B/A ratio and decreased by 57% by each unit increase in SA level. B/A ratio had the AUC of 0.45 for disease severity prediction with 71% sensitivity and 22% specificity. Conclusion: The results showed that B/A ratio and SA levels are associated with mortality in COVID–19 patient, while they had low predictive value for disease severity. High B/A ratio is, additionally, associated with disease severity. Therefore, we suggest to use this marker for clinical assessment of patients with COVID–19.