Procalcitonin Has Good Accuracy for Prognosis of Critical Condition and Mortality in COVID-19: A Diagnostic Test Accuracy Systematic Review and Meta-analysis

Several reports have determined that changes in white blood cell counts and inflammatory biomarkers are related to disease outcome of coronavirus disease 2019 (COVID-19) and they can be utilized as prognostic biomarkers. For introducing a factor as a diagnostic/prognostic biomarker, diagnostic test accuracy (DTA) systematic review and meta-analysis are recommended. For the first time, we aimed to determine the accuracies of white blood cell counts and inflammatory biomarkers for prognosis of COVID-19 patient’s outcome by a DTA meta-analysis. Until August 24, 2020, we searched Web of Sciences, Scopus, and MEDLINE/PubMed databases to achieve related papers. Summary points and lines of included studies were calculated from 2×2 tables by bivariate/hierarchical models. Critical condition and mortality were considered as outcomes. A total of 13387 patients from 28 studies were included in this study. Six biomarkers containing leukocytosis, neutrophilia, lymphopenia, increased level of C-reactive protein, procalcitonin (PCT), and ferritin met the inclusion criteria. Analysis of the area under the curve (AUCHSROC) indicated that the PCT was the only applicable prognostic biomarker for critical condition and mortality (AUCHSROC=0.80 for both conditions). Pooled-diagnostic odds ratios were 6.78 (95% CI, 3.65-12.61) for prognosis of critical condition and 13.21 (95% CI, 3.95-44.19) for mortality. Other biomarkers had insufficient accuracies for both conditions (AUCHSROC 0.80). Among evaluated biomarkers, only PCT has good accuracy for the prognosis of both critical condition and mortality in COVID-19 and it can be considered as a single prognostic biomarker for poor outcomes. Also, PCT has more accuracy for the prognosis of mortality in comparison to critical conditions.