| Supine (n = 30) | Upright (n = 282) | p value* | |
| Pure liquid reflux (%) | 0 (0–58.7) | 43.4 (17.9–65.0) | 0.122 |
| Proximal reflux events (%) | 0 (0–0) | 48.3 (17.5–71.7) | 0.009 |
| Reflux bolus clearance time (s) | 10.4 (6.8–104.0) | 10.4 (6.2–13.1) | 0.310 |
| Bolus burden (s) | 87.5 (32.8–456.3) | 59.9 (11.1–115.7) | 0.176 |
| Nadir pH | 4.7 (0.9–5.1) | 5.5 (4.3–5.9) | 0.116 |
| Acid reflux (%) | 0 (0–0) | 1.1 (0–50.6) | 0.374 |
| Acid burden (s) | 0 (0–165.7) | 0 (0–0) | 0.273 |
| Acid clearance time (s) | 5.5 (0–47) | 3.5 (0–17) | 0.655 |
| Preceding acid reflux (%) | 0 (0–0) | 18.3 (0–64.9) | 0.060 |
| Preceding weakly acidic reflux (%) | 0 (0–84.2) | 92.5 (68.3–100) | 0.003 |
Values are medians (interquartile range).
*Wilcoxon signed rank test.