Table 3. Percentage recovery of premoistened swabs.
| Recovery method | Mean | Median | SD | Range | 95% CIa | pb |
|---|---|---|---|---|---|---|
| All swabs | ||||||
| All | 14.3 | 9.4 | 14.9 | 0.4–63.9 | 11.2 to 17.4 | |
| Extractionc | 19.7 | 14.4 | 15.5 | 4.8–63.9 | 16.3 to 23.1 2.5 to 4.4 | < 0.01 |
| No extraction | 3.5 | 2.7 | 3.1 | 0.4–13.5 | ||
| Vortex | 26.7 | 23.7 | 18.9 | 1.4–29.0 | 20.8 to 32.6 11.0 to 14.5 | < 0.01 |
| Sonication | 12.7 | 13.0 | 5.6 | 4.8–63.9 | ||
| Cotton swabs | ||||||
| All | 20.0 | 13.3 | 18.1 | 2.6–62.5 | 13.5 to 26.5 | |
| Extraction | 27.7 | 20.0 | 17.7 | 7.3–62.5 | 16.7 to 38.7 3.3 to 6.1 | < 0.01 |
| No extraction | 4.7 | 4.0 | 2.2 | 2.6–9.7 | ||
| Vortex | 41.7 | 43.7 | 14.6 | 23.9–62.5 | 33.7 to 51.8 11.3 to 15.3 | < 0.01 |
| Sonication | 13.6 | 13.3 | 3.2 | 7.3–19.5 | ||
| Macrofoam swabs | ||||||
| All | 22.5 | 16.7 | 17.5 | 1.8–63.9 | 16.3 to 28.8 | |
| Extraction | 30.7 | 29.7 | 15.9 | 7.0–63.9 | 20.8 to 40.5 3.9 to 8.7 | < 0.01 |
| No Extraction | 6.3 | 6.5 | 3.9 | 1.8–13.5 | ||
| Vortex | 43.6 | 44.9 | 11.1 | 30.4–64.0 | 36.8 to 50.5 14.0 to 21.3 | < 0.01 |
| Sonication | 17.7 | 16.7 | 5.9 | 7.0–29.0 | ||
| Polyester swabs | ||||||
| All | 7.7 | 6.4 | 5.3 | 0.5–16.5 | 5.8 to 9.6 | |
| Extraction | 10.6 | 11.1 | 4.1 | 4.8–16.5 | 8.1 to 13.1 1.4 to 2.5 | 1.0 |
| No Extraction | 2.0 | 2.0 | 1.0 | 0.5–3.4 | ||
| Vortex | 9.9 | 10.0 | 3.8 | 4.8–14.4 | 7.5 to 12.3 8.5 to 13.9 | 1.0 |
| Sonication | 11.2 | 12.3 | 4.4 | 4.8–16.5 | ||
| Rayon swabs | ||||||
| All | 7.0 | 6.0 | 6.8 | 0.4–24.0 | 4.6 to 9.4 | |
| Extraction | 10.0 | 8.1 | 6.4 | 1.4–24.1 | 6.0 to 14.0 0.5 to 1.4 | 1.0 |
| No extraction | 1.0 | 0.9 | 0.7 | 0.4–2.9 | ||
| Vortex | 11.5 | 11.5 | 7.9 | 1.4–24.1 | 6.6 to 11.2 5.7 to 11.3 | 1.0 |
| Sonication | 8.5 | 7.5 | 4.4 | 2.5–18.9 | ||
aCI, confidence interval. bAdjusted for multiple comparisons by Bonferroni correction. cVortex and sonication methods combined.