Figure 1From: Probiotics' effects on the incidence of nosocomial pneumonia in critically ill patients: a systematic review and meta-analysisFlow chart of study selection. Pooled ORs were calculated using the Mantel-Haenszel (M-H)Estimator. Study-level data were pooled using a random-effects model when I2 was > 50% or a fixed-effects model when I2 was < 50%.Back to article page