Fig 1.
A flow chart showing the reported COVID-19-positive cases amongst veterans with and without the records of serum PCT test results between March 1, 2020, and February 28, 2022.
Table 1.
Characteristics of 27,154 COVID-19-positive US veterans with at least one PCT measurement documented in their medical records between 01 March 2021 and 28 February 2022.
*Unknown in the race, age, and BMI categories are those without any entry in the respective fields.
Table 2.
Trend trajectories showing the changes in the serum PCT values and recorded COVID-19 severity outcomes of hospitalized veterans (n = 11,833; 43.5% of the study cohort) with two or more serial measurements.
Table 3.
Reported cases of pneumonia and antibiotic use within the study cohort of 27,154 COVID-19-positive US veterans.
Fig 2.
Boxplots showing a 5-number summary (minimum, first quartile, median, third quartile, and maximum) for first and last serum PCT levels and stratified based on final outcomes.
The majority of the first test values were obtained within 2–16 days of hospitalization, while the last value was immediately prior to the reported outcomes of hospital discharge, mechanical ventilation, or in-hospital death. The boxes extend from the 25th to the 75th percentile, with whiskers extending to the minimum and maximum points. Outliers are not shown in the box plot.
Fig 3.
Forest plots showing the hazard ratios for mechanical ventilation and in-hospital death.
Model 1 is unadjusted. Model 2 adjusted for demographic and comorbidity conditions (i.e., adjusted for age, race, BMI, history of CKD, Heart failure, hypertension, liver disease, and diabetes), Model 3 adjusted for demography, comorbidity conditions (Model 2) as well as pneumonia (presence or absence) and antibiotic use (used or not used). Model 4 adjusted for all covariates of Model 3 and lab test results (CRP, WBC, and lactate).
Fig 4.
Kaplan–Meier plots for the probability of mechanical ventilation use (A) survival (B) for PCT > 0.2 ng/ml (solid black lines) and PCT ≤ 0.2ng/ml (broken black lines).