Table 3. Spearman correlation coefficients (r) for percentage positivity of diagnostic tests and wastewater Ct values within and between variable groupings, Fulton County Jail, Atlanta, Georgia, USA, October 20, 2021‒May 4, 2022*.
| Diagnostic test | r (p value) |
||
|---|---|---|---|
| PCR | Rapid antigen | Total | |
| PCR | Referent | 0.91 (<0.01) | 0.78 (<0.01) |
| Rapid antigen | Referent | 0.97 (<0.01) | |
| Total |
|
|
Referent |
| Wastewater and diagnostic correlation¶ | |||
| Wastewater Ct values | −0.54 (0.048) | −0.64 (<0.01) | −0.67 (<0.01) |
*Percentage positivity for each category was computed by dividing the number of positive test results in 1 week by the total number of tests administered for the same week. Each datapoint is correlated with all other datapoints; none are grouped based on date or other variables. Ct, cycle threshold. †Based on wastewater Ct values.