Ventilator‐free days
Study	High PEEP	Low PEEP	P value
Brower 2004	Means: 13.8	Means: 14.5	0,50
	SD: 10.6	SD: 10.4
	No. of patients: 276	No. of patients: 273
Cavalcanti 2017	Means: 5.3	Means: 6.4	0,03
	SD: 8	SD: 8.6
	No. of patients: 501	No. of patients: 509
Hodgson 2019	Median: 16	Median: 14.5	0,95
	Interquartile range: 0‐21	Interquartile range: 0‐21.5
	No. of patients: 57	No. of patients: 56
Kacmarek 2016	Median: 8	Median: 7	0,53
	Interquartile range: 0‐20	Interquartile range: 0‐20
	No. of patients: 99	No. of patients: 101
Mercat 2008	Median: 7	Median: 3	0,04
	Interquartile range: 0.0‐19	Interquartile range: 0.0‐17
	No. of patients: 385	No. of patients: 382
Talmor 2008	Median: 11.5	Median: 7	0,50
	Interquartile range: 0.0‐20.3	Interquartile range: 0.0‐17
	No. of patients: 30	No. of patients: 31
Villar 2006	Means: 10.9	Means: 6	0,008
	SD: 9.4	SD: 7.9
	No. of patients: 50	No. of patients: 45