Table 6—

Combined analysis for tidal volume(VT) in chronic obstructive pulmonary disease nonrandomised controlled trials

First author [Ref.]Favours bilevel nFavours control nMD±seWeight %MD (random) 95% CI
Ambrosino 2577382.0000±58.266621.59382.00 (267.80–496.20)
Highcock 1888164.0000±165.188213.03164.00 (−159.76–487.76)
Lien 26111150.0000±54.355721.8650.00 (−56.54–156.54)
Lin 27101223.0000±13.940123.6823.00 (−4.32–50.32)
Nava 1767380.0000±81.185819.85380.00 (220.88–539.12)
Total4243100195.64 (21.97–369.31)
  • MD: mean difference; CI: confidence interval. Comparison: crossover trials of bilevel noninvasive positive pressure ventilation versus all modalities. Outcome: VT mL. Test for heterogeneity: Chi squared = 53.19, df = 4 (p<0.00001), I2 = 92.5%. Test for overall effect: Z = 2.21 (p = 0.03).