Table 1 (abstract A10). Data are expressed as number and (percentage), median and [interquartile range] or mean and standard deviation. Primary outcome balanced according to propensity score weighting procedure for the variables used in the propensity score estimation. For secondary outcomes we defined as “baseline” arterial blood gas (ABG) the worst sample collected during the first 24 h after ICU admission

Unadjusted primary outcome

 Ventilator-free days (range 28 days)

26 [19–26]

12 [2–20]

25 [21–26]

0,002

0,001

0,966

 < 0,001

Adjusted primary outcomes

Estimate coefficent

Standard Error

p-value

 Early PP vs Late PP

9,42

 < 0,001

 < 0,001

 Ealrly PP vs Supine

1,19

0,656

0,656

 Supine vs Late PP

8,23

0,007

0,007

Secondary Outcomes

 Baseline

  PaO₂/FiO₂

215 ± 57

182 ± 61

224 ± 54

0,057

0,117

0,537

0,057

  Driving Pressure cmH2O

12 ± 2

11 ± 1

11 ± 2

0,594

0,703

0,937

0,703

  Crs ml/cmH2O

34 ± 10

36 ± 6

36 ± 9

0,672

0,741

0,741

0,741

 At the end of PP

  PaO₂/FiO₂

330 ± 65

250 ± 62

-

 < 0,001

-

-

-

  Driviing Pressure cmH2O

11 ± 1

12 ± 3

-

0,733

-

-

-

  Crs ml/cmH2O

39 ± 13

33 ± 6

-

0,435

-

-

-

 12 h after re-supination

  PaO₂/FiO₂

332 ± 70

230 ± 53

-

 < 0,001

-

-

-

  Driviing Pressure cmH2O

8 ± 6

14 ± 1

-

0,041

-

-

-

  Crs ml/cmH2O

48 ± 9

37 ± 4

-

0,017

-

-

-

 72 h after PGD diagnosis

  PaO₂/FiO₂

309 ± 72

242 ± 33

250 ± 39

0,002

0,002

0,002

0,261