Table 2

Overall results of the meta-analysis using the fixed effect model

Outcome measureStudies nWeighted averaged effect-sizeNatural units95% CIZ-statisticHomogeneity Q-statisticStudies needed# n
Inspiratory muscle strength PI,max150.5610.5 cmH2O0.35–0.775.27*16.83≥77
Inspiratory muscle endurance MVV40.212.8 L·min−1−0.29–0.700.821.38
Inspiratory muscle endurance s70.41154.2 s0.14–0.682.94**6.67≥14
Inspiratory muscle endurance cmH2O41.1610.3 cmH2O0.67–0.154.67*5.39≥10
Functional exercise capacity 6- or 12MWD80.2248.1 m−0.05–0.481.582.58
Laboratory exercise capacity VO2,max50.04−0.04 L·min−1−0.36–0.29−0.242.50
Laboratory Exercise capacity VE,max50.03−1.5 L·min−1−0.03–0.350.165.49
Dyspnea-Borg exercise-related5−0.55−1.5−0.90–0.19−3.10**3.69≥10
Dyspnoea-TDI rest22.32.71.44–3.155.28**4.14≥14
  • CI: confidence interval

  • PI,max: maximum static inspiratory alveolar pressure

  • MVV: maximal voluntary ventilation

  • 6- or 12MWD: 6- or 12-min walking distance

  • VO2,max: maximal oxygen consumption

  • VE,max: maximal minute ventilation

  • TDI: transitional dyspnoea index

  • #: studies needed for p>0.05

  • **: p<0.01

  • ***: p<0.001