Meta-analysis of randomised controlled trials for post-bronchodilator (BD) outcomes stratified by age group

Outcome or subgroupStudies nParticipants nStatistical methodEffect estimatep-valueI2GRADE
ΔPost-BD FEV1 % pred27894MD (Random, 95% CI)0.61 (−0.31–1.54)0.1971%Moderate#
 Adults13970MD (Random, 95% CI)1.54 (0.87–2.21)<0.0001Moderate#
 Children23924MD (Random, 95% CI)0.20 (−0.49–0.90)0.5712%High
ΔPost-BD FEV1 mL1729MD (Fixed, 95% CI)−40.00 (−115.38–35.38)0.30Moderate#
 Adults00MD (Fixed, 95% CI)
 Children1729MD (Fixed, 95% CI)−40.00 (−115.38–35.38)0.30Moderate#
ΔPost-BD FEV1 SMD28894SMD (Random, 95% CI)0.06 (−0.03–0.15)0.1869%Moderate#
 Adults13970SMD (Random, 95% CI)0.14 (0.08–0.21)<0.0001Moderate#
 Children24924SMD (Random, 95% CI)0.02 (−0.05–0.09)0.5715%High
ΔPost-BD FVC % pred1729MD (Fixed, 95% CI)−0.20 (−1.40–1.00)0.74Low#,
 Adults00MD (Fixed, 95% CI)
 Children1729MD (Fixed, 95% CI)−0.20 (−1.40–1.00)0.74Low#,
ΔPost-BD FVC mL1729MD (Fixed, 95% CI)−60.00 (−119.99– −0.03)0.05Low#,
 Adults00MD (Fixed, 95% CI)
 Children1729MD (Fixed, 95% CI)−60.00 (−119.99– −0.03)0.05Low#,
ΔPost-BD FVC SMD1729SMD (Fixed, 95% CI)−0.02 (−0.17–0.13)0.77Low#,
 Adults00SMD (Fixed, 95% CI)
 Children1729SMD (Fixed, 95% CI)−0.02 (−0.17–0.13)0.77Low#,
ΔPost-BD FEV1/FVC % pred00MD (Fixed, 95% CI)
 Adults00MD (Fixed, 95% CI)
 Children00MD. (Fixed, 95% CI)
ΔPost-BD FEV1/FVC ratio1729MD (Fixed, 95% CI)0.70 (−0.08–1.48)0.08Low#,
 Adults00MD (Fixed, 95% CI)
 Children1729MD (Fixed, 95% CI)0.70 (−0.08–1.48)0.08Low#,
ΔPost-BD FEV1/FVC SMD1729SMD (Random, 95% CI)0.13 (−0.01–0.28)0.07Low#,
 Adults00SMD (Random, 95% CI)
 Children1729SMD (Random, 95% CI)0.13 (−0.01–0.28)0.07Low#,

FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; MD: mean difference; SMD: standardised mean difference. #: GRADE score downgraded for heterogeneity or inconsistency of results between studies; : GRADE score downgraded for imprecision, 95% CI includes important benefit and potential harm.