Table 1.

Characteristics of included studies

Authors	Year	Design	Country	Patient number	Age (mean)	Male (%)	Mean MV (days)	Mean PS	Intervention 1	Intervention 2
Xirouchaki et al. [4]	2008	RCT	Greece	208	60.9 (years)	66.3	4.0	APACHE II, 15.5	PAV+: initial assist 60–80%, reduced by 10–20% per hour. Extubation was performed at 10–20% assist.	PSV: initial PIP 20–25 cmH2O, reduced by 2–5 cmH2O per hour. Extubation was performed at PS 10–12 cmH2O.
Sasikumar et al. [27]	2013	RCT	India	23	48.6 (years)	69.6	NR	APACHE II, 20.7	PAV+: the protocol for PAV+ setting was not available.	PSV: the protocol for PSV setting was not available.
Elganady et al. [28]	2014	RCT	Egypt	60	59.7 (years)	81.7	NR	NR	PAV: initial assist 70%, reduced by 10–20% every 2 h. Extubation was performed at 10–20% assist.	PSV: initial PEEP 5 cmH2O, initial pressure support 5~8 cmH2O. No reduction during the trial. Extubation was performed at 120 min.
Teixeira et al. [29]*	2015	RCT	Brazil	160	44.5 (years)	65.6	6.6	APACHE II, 22.7	PAV+: initial assist and the method for reduction were not available. Extubation was performed at 40% assist.	PSV: pressure support with 7 cmH2O. No reduction method was mentioned. The timing for extubation was not available.
Bosma et al. [30]	2016	RCT	Canada	50	64.8 (years)	50.0	5.8	APACHE II, 26.5	PAV+: initial assist 70%, reduced by the judgment of a respiratory therapist every 2 to 3 h.	PSV: initial PS 15 cmH2O, reduced by the judgment of a respiratory therapist every 2 to 3 h.
Botha et al. [31]	2018	RCT	Australia	50	63.2 (years)	59.2	3.4	APACHE III, 76.7; SASP, 45.5	PAV+: initial assist 70%, reduced by 10%. Extubation was performed at 30% assist.	PSV: initial PS was set at patient’s need; the reduction method was not mentioned. Extubation was performed at PS 10 cmH2O.
Salama et al. [32]	2018	RCT	Egypt	150	NA	NA	NA	NA	PAV+	PSV

*Three-arm study