Increasing plasma calprotectin (S100A8/A9) is associated with 12-month mortality and unfavourable functional outcome in critically ill COVID-19 patients

Table 1 Clinical characteristics at baseline stratified by 12-month mortality

	All patients	Survivors	Non-survivors	p-value
	N = 498	N = 298	N = 198
Age (years)	66 [56–73]	61 [52–68]	72 [66–77]	< 0.001
Male sex	367 (74%)	218 (73%)	147 (74%)	0.79
BMI (kg/m²)	30 [27–35]	31 [27–36]	29 [26–33]	< 0.001
Smoking	220 (44%)	109 (38%)	111 (56%)	< 0.001
Diabetes mellitus	154 (31%)	85 (28%)	68 (34%)	0.17
Hypertension	270 (55%)	149 (51%)	121 (62%)	0.023
Symptomatic days before ICU	11 [8–15]	10 [7–14]	12 [9–16]	0.022
COPD or severe asthma	94 (19%)	51 (17%)	43 (22%)	0.20
Clinical Frailty Scale	3 [2–4]	3 [2, 3]	3 [2–4]	< 0.001
Charlson Comorbidity Index	3 [2–4]	2 [1–3]	4 [3–5]	< 0.001
SOFA	8 [5–9]	7 [4–9]	8 [5–10]	0.043
SAPS 3	60 [50–69]	56 [47–66]	66 [56–75]	< 0.001
Laboratory findings
Creatinine (μmol/L)	75 [60–102]	70[58–93]	86 [65–125]	< 0.001
Calprotectin day 0 (mg/L) (n = 484)	7.39 [4.36–11.5]	6.72 [4.01–10.4]	8.62 [4.99–14.4]	< 0.001
Calprotectin day 7 (mg/L) (n = 356)	4.13 [2.30–7.01]	3.52[1.99–62]	6.01 [3.02–10.8]	< 0.001
Clinical parameters
P/F ratio (min) (kPa)^a	10 [8.0–12]	10 [8.0–13]	9 [7.0–14]	0.037
IMV	357 (72%)	196 (66%)	160 (81%)	< 0.001
CRRT	74 (15%)	45 (15%)	29 (15%)	0.89
IMV total days (n = 357)^a	9 [5–18]	8 [5–17]	13 [7–21]	0.001
LOS ICU (n = 498)	10 [5–17]	9 [5–18]	10 [5–16]	0.93
LOS Hospital (n = 498)	23 [15–42]	23 [14–44]	22 [15–37]	0.95

Results are expressed as n (%) or median [IQR]
BMI body mass index, ICU intensive care unit, COPD chronic obstructive pulmonary disease, SOFA Sequential Organ Failure Assessment, SAPS 3 Simplified Acute Physiology Score, P/F ratio defined as P_aO₂ (arterial partial pressure of oxygen)/F_iO₂ (fraction of inspired oxygen), IMV invasive mechanical ventilation, CRRT continuous renal replacement therapy, LOS length of stay, ICU intensive care unit
^aLowest P/F ratio on ICU day 1

ISSN: 2052-0492