Table 1.

Studies of prone position in nonintubated patients

Study rank, first author	Country	Kind of study	Inclusion	Location	Oxygen	HFNC	NIV	CPAP	Other	Criteria to prone	Planned proning session duration	N prone	N supine
1. Barker	UK	O,R	March–June 2020	S, ICU	4	0	16	0	0	Not defined	As long as possible	10	10
2. Ferrando	Spain	O,P	March–June 2020	M, ICU	0	199	0	0	0	Not defined	16 h	55	144
3. Jagan	USA	O,R	March–May 2020	S, Other	NA	NA	NA	NA	NA	Not defined	NA	40	65
4. Jayakumar	India	RCT	NA	M, Other	56	1	2	0	1	SpO2 ≥92% O2 >4 l/min or PaO2/FIO2 100–300 mmHg	6 h	30	30
5. Johnson	USA	RCT	April–August 2020	S, Other	11	0	0	0	0	Not defined	2 h	15	15
6. Jouffroy	France	O,R	February–April 2020	M, ICU	2	37	0	1	0	Clinican discretion	3 h	40	339
7. Kharat	Switzerland	RCT	April 2020	M, Acute Care	27	0	0	0	0	SpO2 90–92% O2 1–6 l/min	As long as possible	10	17
8. Liu	China	O,R	January–March 2020	S, Other	NA	NA	NA	NA	NA	Not defined	10–14 h	13	16
9. Padrao	Brazil	O,R	March–April 2020	S, ER	93	72	0	0	0	Not defined	4 h	57	109
10. Prudhomme	France	O,R	March–April 2020	M, ER	NA	NA	NA	NA	NA	Not defined	3 h	48	48
11. Perez	Mexico/Ecuador	O,R	May–June 2020	M, ER &ICU	744	83	0	0	0	Clinican discretion	2 h	505	322
12. Rosen	Sweden	RCT	October 2020–February 2021	M, Other	0	60	15	0	0	PaO2/FIO2 ≤50 mmHg	16 h	36	39
13. Simioli	Italy	O,R	March–April 2020	S, Step Down	0	6	0	23	0	Not defined	10 h	18	11
14. Sryma	India	O,P	NA	ICU	42	1	2	0	0	Not defined	8 h	30	15
15. Taylor	USA	RCT	June–August 2020	M, Other	38	0	1	0	0	SpO2 <93% or O2 >3 l/min	As long as possible	27	13
16. Tonelli	Italy	O,R	March–June 2020	M, ICU	0	69	19	25	0	Not defined	3 h	38	76
17. Zang	China	O,P	February–April 2020	S, ICU	0	15	15	0	0	Not defined	3–8 h	23	37

CPAP, continuous positive airway pressure; ER, emergency room; HFNC, high flow nasal cannula; M, multicenter; NA, not available; NIV, noninvasive ventilation; O, observational; P, prospective; R, retrospective; RCT, randomized controlled trial; S, single center.