Measurements of gastric pH by each technique
| Parameters | pH level | P value |
| pH measurements* | <0.01 | |
| pH meter | 5.83 (5.12–6.61) | – |
| pH strip | 5.50 (5.00–6.00) | – |
| pH liquid | 5.75 (5.25–6.25) | – |
| Differences between techniques† | ||
| pH strip and pH meter | −0.27 (−0.49–0.03) | <0.01 |
| pH liquid and pH meter | −0.02 (−0.41–0.43) | 0.04 |
| pH liquid and pH strip | 0.50 (−0.25–0.75) | <0.01 |
*Friedman test.
†Pairwise comparison by Dunn’s test adjusted with Bonferroni method.