Table 2.

Results of subgroup analyses and sensitivity analysis

Subgroups and sensitivity analysis	Time-skill SMD and 95%CI [number of studies]	Behavior performance SMD and 95%CI [number of studies]	Examination scores SMD and 95%CI [number of studies]
Airway management techniques
FL	−2.17 (−6.77,2.42) [n = 2]	0.59 (0.03,1.16) [n = 3]	0.43 (−0.16,1.03) [n = 4]
DL	0.13 (−0.56,0.81) [n = 2]	0.28 (−0.02,0.58) [n = 2]	NA
Sensitivity analysis of RCTs	−0.13 (−0.82, 0.57) [n = 4]	0.30 (0.06, 0.54) [n = 6]	0.38 (−0.24, 1.00) [n = 4]

CI confidence interval, SMD standardized mean difference, DL direct laryngoscopy or/and intubation, FL flexible laryngoscopy or bronchoscopy, RCTs randomized controlled trials, NA not available