Combined analysis for maximal inspiratory and expiratory mouth pressure(PI,max and PE,max, respectively) in chronic obstructive pulmonary disease nonrandomised controlled trials
| First author [Ref.] | Favours bilevel n | Favours control n | MD±se | Weight % | MD (random) 95% CI |
| PI,max analysis | |||||
| Lien 26 | 11 | 11 | 0.4000±12.8142 | 3.35 | 0.40 (−24.72–25.52) |
| Lin 27 | 10 | 12 | 5.0000±2.3839 | 96.65 | 5.00 (0.33–9.67) |
| Total | 21 | 23 | 100 | 4.85 (0.25–9.44) | |
| PE,max analysis | |||||
| Lien 26 | 11 | 11 | 1.0000±10.3830 | 4.40 | 1.00 (−19.35–21.35) |
| Lin 27 | 10 | 12 | 5.0000±2.2265 | 95.60 | 5.00 (0.64–9.36) |
| Total | 21 | 23 | 100 | 4.82 (0.56–9.09) |
MD: mean difference; CI confidence interval. Comparison: crossover trials of bilevel noninvasive positive pressure ventilation versus all modalities. Outcome: PI,max cmH2O or PE,max cmH2O. Test for heterogeneity in PI,max analysis: Chi squared = 0.12, df = 1 (p<0.72), I2 = 0%. Test for overall effect: Z = 2.07 (p = 0.04). Test for heterogeneity in PE,max analysis: Chi squared = 0.14, df = 1 (p<0.71), I2 = 0%. Test for overall effect: Z = 2.22 (p = 0.03).