TABLE 2.
Group A Streptococcus real-time PCR results
| Collection group | No. of swab pairs | % positive |
% concordant (95% CI) | No. of HCW-/self-collection results |
|||||
|---|---|---|---|---|---|---|---|---|---|
| Concordant |
Discordant |
||||||||
| HCW | Self | Pa | −/− | +/+b | +/− | −/+ | |||
| Overall | 402 | 33.3 | 34.3 | 0.41 | 94.0 (91.3, 96.0) | 254 | 124 | 10 | 14 |
| First swab: self | 203 | 35.0 | 36.0 | 0.53 | 95.1 (91.2, 97.3) | 126 | 67 | 4 | 6 |
| First swab: HCW | 199 | 31.7 | 32.7 | 0.59 | 93.0 (88.5, 95.8) | 128 | 57 | 6 | 8 |
| No prior swab collection training | 363 | 34.2 | 35.0 | 0.53 | 93.7 (90.7, 95.7) | 226 | 114 | 10 | 13 |
| Prior swab collection training | 39 | 25.6 | 28.2 | 0.32 | 97.4 (86.8, 99.5) | 28 | 10 | 0 | 1 |
| Self-collection individual | |||||||||
| Parent | 196 | 39.3 | 38.8 | 0.78 | 93.4 (89.0, 96.1) | 113 | 70 | 7 | 6 |
| First swab: non-HCW (all) | 98 | 40.8 | 40.8 | 1.0 | 93.9 (87.3, 97.2) | 55 | 37 | 3 | 3 |
| First swab: non-HCW (no prior swab collection training) | 86 | 40.7 | 40.7 | 1.0 | 93.0 (85.6, 96.8) | 48 | 32 | 3 | 3 |
| First swab: HCW | 98 | 37.8 | 36.7 | 0.71 | 92.9 (86.0, 96.5) | 58 | 33 | 4 | 3 |
| Self | 206 | 27.7 | 30.1 | 0.13 | 94.7 (90.7, 97.0) | 141 | 54 | 3 | 8 |
| First swab: non-HCW (all) | 105 | 29.5 | 31.4 | 0.32 | 96.2 (90.6, 98.5) | 71 | 30 | 1 | 3 |
| First swab: non-HCW (no prior swab collection training) | 93 | 30.1 | 32.3 | 0.32 | 95.7 (89.5, 98.3) | 62 | 27 | 1 | 3 |
| First swab: HCW | 101 | 25.7 | 28.7 | 0.26 | 93.1 (86.4, 96.6) | 70 | 24 | 2 | 5 |
a
P values from McNemar's test comparing the percentages of positive results between HCW-collected and self-collected specimens. Of note, the positivity rates of the levels for the factors in the table did not differ significantly (data not shown).
b
Crossing-point values among pairs which were positive via both methods are summarized in Table 3.