Table 3.
Linear mixed-effect model analyses for Ct values stratified by exposures.
| Exposure | Mean Ct value [95% CI] | Mean difference of Ct value [95% CI] | P value |
|---|---|---|---|
| Symptoms* | |||
| Asymptomatic patients | 37.17 [34.75; 39.60] | Ref | |
| Symptomatic patients | 35.77 [35.16; 36.38] | − 1.40 [− 3.90; 1.09] | 0.267 |
| Duration of symptoms* | |||
| Symptom duration > 4 days | 36.74 [35.88; 37.59] | Ref | |
| Symptom duration ≤ 4 days | 34.99 [34.21; 35.78] | − 1.74 [− 2.90; − 0.57] | 0.004 |
| Variant of SARS-CoV-2* | |||
| Wildtype | 35.80 [34.43; 37.18] | Ref | |
| B.1.1.7 | 35.71 [35.05; 36.36] | − 0.10 [− 1.63; 1.42] | 0.894 |
| Method of air sampling | |||
| Exhaling | 35.54 [34.22; 36.86] | Ref | |
| Singing/loud talking | 35.92 [35.02; 36.83] | 0.38 [− 0.90; 1.67] | 0.545 |
Ct cycle threshold, CI confidence interval, IQR interquartile range, Ref reference, SARS-CoV-2 severe acute respiratory coronavirus 2.
*Samples obtained through singing/loud talking.