Effect of timing of intubation on clinical outcomes of critically ill patients with COVID-19: a systematic review and meta-analysis of non-randomized cohort studies

Table 1 Characteristics of individual studies and patient populations

First author	Country	Type of study	Patient population, N	Early intubation, N	Late intubation, N	No intubation, N	Prior trial of HFNC or NIV, N	Female sex, %	Age, years^a	SOFA at ICU admission^a
COVID-ICU Group [20]	France Switzerland Belgium	Multicenter, prospective	4244	2635	741	810	NA	26.0	63.0 [54.0–71.0]	5.0 [3.0–8.0]
Grasselli [21]	Italy	Multicenter, retrospective	3988	2929	164	NA	NA	20.0	NA	NA
Hernandez-Romieu [22]^b	United States	Multicenter, retrospective	175	133	42	NA	78	44.6	66.0 [56.0–75.0]	9.0 [7.0–12.0]
Karagiannidis^c [13]	Germany	Multicenter, retrospective	1727	1318	141	145	141	33.6	71.0 [60.0–79.0]	NA
Lee^d [23]	Korea	Multicenter, retrospective	47	23	16	8	NA	40.4	70.0 [63.0–77.0]	3.6 (3.2)
Matta^e [24]	United States	Single-center, retrospective	111	76	35	NA	81	46.0	68.0 (11.3)	7.6 (3.2)
Mellado-Artigas [25]	Spain Andorra	Multicenter, prospective	468	312	49	NA	92	30.8	61.7 (11.5)	5.8 (2.4)
Pandya^f [26]	United States	Single-center, retrospective	75	37	38	NA	NA	42.7	65.0 (14.3)	NA
Roedl [27]	Germany	Multicenter, retrospective	223	128	39	56	46	27.0	69.0 [58.0–77.5]	5.0 [3.0–9.0]
Saida [18]	Tunisia	Single-center, retrospective	10	4	3	3	1	20.0	51.8 (6.3)	NA
Siempos [14]	Greece	Single-center, retrospective	42	14	18	6	11	19.0	65.0 [58.0–71.0]	4.0 [4.0–6.0]
Zuccon [19]	Italy	Single-center, retrospective	54	25	23	6	23	18.5	NA	NA

N = number, SOFA = sequential organ failure assessment, ICU = intensive care unit, NA = not available, HFNC = high flow nasal cannula, NIV = noninvasive mechanical ventilation
^aData on age and SOFA are presented as means (SD) or medians [IQR], as provided by the individual studies
^bIn the study by Hernandez-Romieu et al., there were three groups: < 8 h, 8–24 h, > 24 h. The first two groups were combined (hence, the two values for age and SOFA) and considered as “early intubation” group for the purpose of this meta-analysis
^cIn the study by Karagiannidis et al., “early” intubation was defined as “non-invasive ventilation (NIV)-failure and intubation within 24 h or intubation without NIV”
^dIn the study by Lee et al., “early” intubation was defined as “intubation/mechanical ventilation and fulfillment of acute respiratory distress syndrome criteria within 24 h”. Data on duration of mechanical ventilation and length of intensive care unit among survivors (rather than among all included patients) were provided in this study
^eIn the study by Matta et al., “early” intubation was defined as “intubation at admission or within 48 h since the onset of increased oxygen requirements”
^fIn the study by Pandya et al., “early” intubation was defined as “intubation within 1.27 days from presentation (median)”

ISSN: 1364-8535