Table 1.

Baseline characteristics of 814 patients with and without significant persistent pain at 3 months

	No or mild symptoms N = 426	Significant pain symptoms N = 388	P value
Gender
Male	301 (70.8%)	240 (62%)	0.01
Female	124 (29.2%)	147 (38%)
Age	58 (± 17)	56 (± 17)	0.2
Height (cm)	171 (± 13)	170 (± 10)	0.1
Weight (kg)	79 (± 19)	81 (± 21)	0.5
Medical history
Hypertension	180 (42.3%)	152 (39.2%)	0.4
Chronic obstructive pulmonary disease	34 (8%)	34 (8.8%)	0.8
Ischemic cardiomyopathy	57 (13.4%)	34 (8.8%)	0.05
Diabetes mellitus	78 (18.3%)	58 (15%)	0.2
History of cancer	91 (21.4%)	74 (19.1%)	0.5
Stroke	12 (2.8%)	12 (3.1%)	0.9
Hypercholesterolemia	79 (18.5%)	61 (15.7%)	0.3
Anxiety and depression syndrome	28 (6.6%)	40 (10.3%)	0.1
Active smoking	109 (25.7%)	102 (26.5%)	0.9
Chronic alcohol intake	62 (14.7%)	66 (17.1%)	0.4
Chronic medication
Paracetamol, NSAID	44 (10.4%)	46 (11.9%)	0.6
Tramadol	14 (3.3%)	19 (4.9%)	0.3
Morphine	15 (3.5%)	19 (4.9%)	0.4
Gabapentin, Pregabalin	19 (4.5%)	25 (6.5%)	0.3
Neuroleptics	22 (5.2%)	30 (7.8%)	0.2
Antidepressant agent	27 (6.4%)	45 (11.8%)	0.01
Cause of admission			< 0.001
Traumatic brain injury	7 (1.6%)	8 (2%)
Stroke	7 (1.6%)	7 (1.8%)
Trauma (non neuro)	37 (8.7%)	87 (22.4%)
Major thoracic surgery	37 (8.7%)	30 (7.7%)
Burn	42 (9.9%)	23 (5.9%)
Sepsis	51 (12%)	21 (5.4%)
COVID-19	36 (8.5%)	37 (9.5%)
Acute respiratory failure	29 (6.8%)	28 (7.2%)
Non-thoracic surgery	116 (27.2%)	89 (22.9%)
Other	64 (15%)	58 (15%)

Chronic pain symptoms were defined as a Numeric Rating Scale ≥ 3, at 3-months after admission. NSAID: Non-Steroidal Anti-Inflammatory Drug. Numeric variables are expressed as mean (± SD). Continuous outcomes were compared with Student's t-test. Discrete outcomes were compared with chi-squared or Fisher’s (£) exact test