Table 5. Correlation between improvement of functional outcomes and clinical parameters (between baseline and 1-month OPD follow-up).

Clinical parameters	Improvements of functional outcomes	Spearman’s rank correlation coefficient	P value
PHQ-9	1-min sit-to-stand	−0.82	0.011
PHQ-9	Gait speed	−0.63	0.039
Age	Gait speed	−0.53	0.036
Total length of stay	Gait speed	−0.67	0.005
Length of stay at ICU	Gait speed	−0.57	0.022
Mechanical ventilation period	Gait speed	−0.56	0.023
Tracheostomy	Gait speed	−0.62	0.011
Albumin	Gait speed	0.65	0.006

OPD = outpatient department, PHQ-9 = Patient Health Questionnaire-9, ICU = intensive care unit.