Table 1.

Characteristics and the quality assessment of the nine studies included.

Study, year	Drug	Abbr.	Patients(N)	Term	Random sequence generation	Allocation concealment	Blinding	Incomplete outcome data addressed	Selective reporting	Other bias
Nazzareno et al., 2018	Ambrisentan	A1-1	201	12 weeks	Yes	Yes	Unclear	Yes	Yes	Unclear
		A1-2	192	12 weeks	Yes	Yes	Unclear	Yes	Yes	Unclear
Channick, 2001	Bosentan	B1	32	20 weeks	Yes	Yes	Unclear	Yes	No	Unclear
Barst et al., 2010		B2	14	16 weeks	Yes	Yes	Unclear	No	Unclear	Unclear
Galiè, 2008		B3	185	6 months	Yes	Yes	Yes	Yes	Yes	Unclear
Lewis, 2002		B4-1	213	16 weeks	Yes	Yes	Unclear	Yes	Unclear	Unclear
		B4-2	33	16 weeks	Yes	Yes	Unclear	Yes	Unclear	Unclear
Humbert et al., 2004		B5	33	16 weeks	Yes	Yes	Unclear	Yes	Unclear	Unclear
Nazzareno et al., 2006		B6	54	16 weeks	Yes	Yes	Yes	Yes	Unclear	Unclear
Robyn, 2011	Sildenafil	S1	234	16 weeks	Yes	Yes	Unclear	Yes	Unclear	Unclear
Carmine et al., 2017		S2	86	24 weeks	Yes	Yes	Unclear	Yes	Unclear	Unclear