Table 5. Patient characteristics by cohort.

	Derivation Cohort (110)	Validation Cohort (83)	p
Age, years**	67 (50–77)	62 (48–72)	0.08
Male n (%)*§	62 (56)	43 (52)	0.561
APACHE II score, points**	17 (13–21)	23.5 (17–29)	0.000
Admission Diagnosis n (%)*§§
Respiratory Disease	30 (27)	15 (18)	0.277
Post Surgery	23 (21)	24 (29)
Sepsis or Septic Shock	17 (15)	9 (11)
Trauma	13 (12)	9 (11)
Neurologic Disease	12 (11)	12 (14)
Cardiac Disease	3 (3)	7 (8)
Others	12 (11)	7 (8)
Days of Mechanical Ventilation, days**	5 (2–7)	5 (2.5–8.5)	0.182

*presented as absolute and relative frequency.

**presented as median and interquartile range and applied Mann-Whitney U test.

^§ Fisher Exact test.

^§§ Chi-square test.