ABSTRACT
Introduction: COVID-19 is an emerging public health problem. It comprises of a large virus family causing varying infection ranging from common cold to more severe infection. Classification of cases into mid, moderate, severe helps for effective management and treatment. CRP is a highly sensitive biomarker for inflammation, tissue damage. Materials and Methods: A retrospective cohort study was done during March 2020 to Feb 2021. Total 2,239 patients were included in the study. CRP levels were measured in hospitalized patients on the day of admission. Statistical Analysis: Continuous variables are presented as Mean ± standard deviation and Median (Q1, Q3). Qualitative variables are presented as frequency and percentage. The continuous variables were compared using independent t test, one-way analysis of variance or Kruskal-Wallis test. Receiver operating characteristic curves (ROC) were constructed to identify the predictability and best cut-offs of variables to differentiate moderate illness from severe-critical illness, severe illness from critical illness, and survivors from non-survivors. A two-tailed P value <0.05 was considered statistically significant. Results: We found a significant increase in CRP values in patients with critical illness in wave-1 and wave-2. The levels of CRP increased as the severity of disease progressed. The CRP had a sensitivity of 71.3% and specificity of 59.8% in critically ill patients in wave-1. In wave-2, the sensitivity of 70.10% and specificity of 56% in critically ill patients. In wave-3, the sensitivity of 75% and specificity of 20.3% in severely ill patients. This indicates that CRP can be used as a marker for disease progression. The Youden index J is 0.3978 and the association criterion is >1.85. Conclusion: CRP is a simple test that helps in initiating primary care. It indicates the severity of disease in COVID-19 infection. CRP can be used as a marker for disease progression and also indicates the severity of lung involvement. © 2022 by the Author(s).