Characteristics of the study population
| Associated reflux episodes | Non-associated reflux episodes | p Value | |
|---|---|---|---|
| Proximal extent (cm) | 9 (8.5–16) | 9 (7–9) | 0.0001 |
| Ascending velocity (cm/s) | 3.1 (2.1–4.8) | 2.8 (2.0–3.9) | 0.159 |
| Nadir pH | 3.15 (1.97–4.12) | 2.75 (2.20–3.77) | 0.394 |
| pH drop | 3.4 (2.47–4.22) | 3.3 (2.55–3.80) | 0.571 |
| Volume clearance time (s) | 17 (12–22) | 14 (12–17) | 0.002 |
| Acid clearance time (s) | 33.5 (10–62.4) | 27.6 (10.6–60.5) | 0.453 |
| Percentage acidic (%) | 66.7 (43.7–88.7) | 70 (50.0–86.6) | 0.367 |
| 15 min acid burden(s) | 2.8 (0–20.3) | 0 (0–15.6) | 0.019 |
| 30 min acid burden(s) | 25.3 (0.5–92.6) | 16.9 (1.7–122.2) | 0.342 |
| 45 min acid burden(s) | 53.2 (2.3–154.1) | 32.9 (4.3–182.5) | 0.167 |
| 60 min acid burden (s) | 38.1 (3.5–194.5) | 46.6 (10.2–268.0) | 0.866 |
| 15 min volume burden (s) | 11.0 (4.4–17.6) | 11.5 (3.3–16.5) | 0.116 |
| 30 min volume burden (s) | 27.8 (15.6–46.0) | 25 (17.0–40.9) | 0.044 |
| 45 min volume burden (s) | 43.9 (26.7–66.8) | 42.9 (28.0–60.7) | 0.486 |
| 60 min volume burden (s) | 56.2 (26.6–87.5) | 57.0 (35.8–85.2) | 0.652 |
| Percentage in upright position (%) | 100 (88.2–100) | 97.4 (93.0–100) | 0.407 |
| Percentage liquid (%) | 42.9 (21.1–63.3) | 39.1 (26.0–60.6) | 0.992 |
Reflux episodes which were associated with cough bursts are compared with reflux episodes which were not associated with cough bursts. All values are shown as median (IQR). The p value was calculated using the Wilcoxon signed-rank test.