Comparing the predictive values of procalcitonin/albumin ratio and other inflammatory markers in determining COVID-19 severity

Objective: To examine the relationship between COVID-19 severity and procalcitonin/albumin ratio (PAR) and compare the PAR with oft-reported inflammatory markers, including procalcitonin, white blood cell (WBC), neutrophil/lymphocyte ratio (NLR) and C-reactive protein (CRP).

Methods: In this retrospective research study conducted at Sanliurfa Training and Research Hospital during May to September 2020; total, 577 adult subjects diagnosed with COVID-19 were included and categorized into two groups based on place of hospitalization: the intensive care unit (ICU) group (n=151) and the general ward (GW) group (n=426). Laboratory test results and demographic characteristics of the subjects were recorded.

Results: PAR, NLR, CRP, WBC, neutrophil and procalcitonin values were markedly higher in the ICU group than in the GW group. On the contrary, lymphocyte count and albumin level were markedly lower. PAR showed positive correlations with WBC, NLR, and CRP. Multivariate analysis showed that advanced age, presence of hypertension, elevated PAR, WBC, NLR, urea and lactate dehydrogenase levels were independent risk factors associated with the need for intensive care in COVID-19 subjects. Among them, the PAR showed the highest odds ratio (5.564) for ICU admission. Additionally, the area under the ROC curve of the PAR (0.888) was markedly greater than that of WBC (0.777), NLR (0.822), CRP (0.842) and procalcitonin (0.870).

Conclusions: This study revealed that PAR was superior to procalcitonin, WBC, NLR and CRP in determining COVID-19 severity. PAR was an important predictor of ICU requirement in COVID-19 cases.