Five studies reported duration of mechanical ventilation, and four
studies reported duration of oxygen therapy. We observed that the
duration of mechanical ventilation (OR -0.72, 95%CI: -0.92 - -0.51,P<0.001) and oxygen therapy duration (OR -6.05, 95%CI:
-6.56 - -5.54, P<0.001) were considerably lower in the
prophylactic caffeine group than in the control group. The
random-effects model was employed because moderate heterogeneity in
duration of mechanical ventilation was identified among the included
studies (I2=52.2%, P=0.079, Figure 3B). We
used a fixed-effects model to evaluate the meta-analysis of the duration
of oxygen therapy (I2=23.5%, P=0.270, Figures
3C).