Analysis and Prediction of False Negative Results for SARS-CoV-2 Detection with Pharyngeal Swab Specimen in COVID-19 Patients: A Retrospective Study

Hui Xu; Li Yan; Chun (Martin) Qiu; Bo Jiao; Yanyan Chen; Xi Tan; Zhuo Chen; Ling Ai; Yaru Xiao; Ailin Luo; Shusheng Li

The higher the position of a KM curve, the more likely were the patients to test positive given the same timespan since getting sick. In other words, they had a shorter time window for testing positive. It was noticeable that the detection of the phrase "GGO" in CT imaging reports reduced the time window for testing positive (Figure 1 A) . In comparison, the detection of "consolidation" extended the time window for testing positive, leading to a higher chance of false negative if the test was taken in earlier time (Figure 1 B) . It was clear that higher levels of basophils and eosinophils delayed the time for testing positive, resulting in a higher likelihood for a false negative (Figure 1 C, D) . Among clinic symptoms, fever was the only one to be associated with the time window by shortening its duration (Figure 1 E) , whereas chest distress was the only symptom to be associated with the time window by extending it (Figure 1 F) .