Prognostic properties of hypoalbuminemia in COVID-19 patients: A systematic review and diagnostic meta-analysis

BACKGROUND: Coronavirus disease 2019 (COVID-19) elicits robust inflammatory reaction that may result in a declining albumin serum level. This meta-analysis aimed to evaluate the prognostic properties of hypoalbuminemia for poor prognosis and factors that may influence the relationship. METHOD: A systematic literature search of PubMed was conducted from inception to April 22, 2021. The main exposure was albumin level below normal range–defined by the included studies. The outcome of interest was composite poor outcome that comprises of mortality, severity, and the requirement of mechanical ventilation or intensive care unit. RESULTS: There were 6200 patients from 19 studies. Meta-analysis showed that hypoalbuminemia was associated with composite poor outcome (OR 6.97 (95% CI 4.20–11.55), p < 0.001; I(2) = 91.3%, p < 0.001). Meta-regression analysis showed that age (p = 0.44), gender (p = 0.76), HT (p = 0.97), DM (p = 0.40), CKD (p = 0.65), liver disease (p = 0.72), and malignancy (p = 0.84) did not affect the association. Subgroup analysis showed that hypoalbuminemia increased mortality (OR 6.26 (95% CI 3.26–12.04), p < 0.001; I(2) = 69.6%, p < 0.01) and severity of the disease (OR 7.32 (95%CI 3.94–13.59), p < 0.001; I(2) = 92.5%, p < 0.01). Pooled diagnostic analysis of hypoalbuminemia yielded a sensitivity of 0.63 (95% CI 0.52–0.72), specificity of 0.81 (95% CI 0.73–0.87), and AUC of 0.77. The probability of poor outcome was 70% in patients with hypoalbuminemia and 24% in patients with normal albumin level. CONCLUSION: Hypoalbuminemia was associated with poor prognosis in COVID-19 patients.