Distance | 1 m | 2 m | 4 m | ANOVA p value† |
---|---|---|---|---|
Total‡ | 52.6 (40.9–67.6)^{a} | 37.3 (28.9–48.0)^{a} | 24.8 (19.2–32.0)^{b} | 0.001 |
Large fraction§ | 27.4 (21.4–34.9)^{a} | 19.9 (15.5–25.5)^{a} | 12.6 (9.7–16.2)^{b} | <0.001 |
Small fraction¶ | 27.6 (21.2–35.9)^{a} | 19.6 (15.0–25.5)^{ab} | 14.3 (10.9–18.7)^{b} | 0.005 |
Duration | 5 min | 15 min | 45 min | |
Total‡ | 14.6 (11.0–19.2)^{a} | 11.9 (8.9–15.7)^{a} | 7.7 (5.4–11.0)^{b} | 0.046 |
Large fraction§ | 4.2 (3.1–5.5)^{a} | 3.9 (2.9–5.2)^{a} | 2.3 (1.5–3.4)^{a} | 0.074 |
Small fraction¶ | 11.9 (9.1–15.6)^{a} | 9.0 (6.7–11.8)^{ab} | 6.2 (4.3–8.8)^{b} | 0.031 |
*Values are means (95% CI). Within sets and rows, a different superscript letter (^{a} or ^{b}) denotes a significant difference (p<0.05) between other distances or durations.
†ANOVA for trend across distance or duration.
‡Total CFU counts represent the P aeruginosa CFUs isolated from all six Andersen Impactor stages (aerosol particles sizes 0.65 to >7.0 µm).
§Large particle fraction CFU counts represent the P aeruginosa CFUs isolated from stages 1, 2 and 3 (aerosol particle sizes >7, 4.7–7.0 and 3.3–4.7 µm, respectively) of the Andersen Impactor.
¶Small particle fraction CFU counts represent the P aeruginosa CFUs isolated from stages 4, 5 and 6 (aerosol particle sizes 2.1–3.3, 1.1–2.1 and 0.65–1.1 µm, respectively) of the Andersen Impactor.