Table 4.

Trim and Fill test results.

Subgroup	Model	RR (95% CI)	p	Heterogeneity
				I2	Phet
ARDS	Fixed-effect	1.55 (1.15–2.10)	0.005	0	0.651
	Random-effect	1.55 (1.15–2.10)	0.005	0	0.651
Cardiac surgery	Fixed-effect	0.80 (0.64–0.99)	0.037	0	0.528
	Random-effect	0.80 (0.64–0.99)	0.037	0	0.528
Organ transplantation	Fixed-effect	0.40 (0.15–1.05)	0.061	0	0.914
	Random-effect	0.40 (0.15–1.05)	0.061	0	0.914

ARDS: acute respiratory distress syndrome; CI: confidence interval; RR: relative risk.