TABLE 2.

Methodological quality of trials included in the meta-analysis

Author (reference)	Year	Randomization method	Blinding	Explanation for withdrawals/dropouts	Jadad score	Allocation concealment	Intention-to-treat analysis
Primary prophylaxis
Pérez-Ayuso et al (12)	2010	Stratified randomization	None	Yes	3	Sealed envelopes	Yes
Tripathi et al (13)	2009	Randomization in batches of 20 patients	None	Yes	3	Sealed envelopes	Yes
Norberto et al (14)	2007	Computer-generated random numbers	None	Yes	3	Sealed envelopes	Yes
Lay et al (15)	2005	Unclear	None	Yes	2	Sealed envelopes	Yes
Thuluvath et al (16)	2005	Unclear	None	Yes	2	Sealed envelopes	Yes
Jutabha et al (17)	2005	A block randomization for each centre	None	Yes	3	Sealed envelopes	Yes
Psilopoulos et al (18)	2005	Table of random numbers	None	Yes	3	Unclear	Yes
Schepke et al (19)	2004	A block randomization for each centre	None	Yes	3	Central randomization	Yes
Lo et al (20)	2004	Table of random numbers	None	Yes	3	Sealed envelopes	Yes
Lui et al (21)	2002	Randomization in batches of 18 patients	None	Yes	3	Sealed envelopes	Yes
Sarin et al (22)	1999	Table of random numbers	None	Yes	3	Unclear	No
De et al (23)	1999	Unclear	None	Unclear	1	Unclear	Yes
Secondary prophylaxis
Ahmad et al (24)	2009	Computer-generated random numbers	None	Yes	3	Sealed envelopes	No
Lo et al (25)	2008	Table of random numbers	None	Yes	3	Sealed envelopes	Yes
Romero et al (26)	2006	Table of random numbers	None	Yes	3	Sealed envelopes	Yes
Sarin et al (27)	2005	Table of random numbers	None	Yes	3	Unclear	Yes
Patch et al (28)	2002	Table of random numbers	None	Yes	3	Sealed envelopes	Yes
Villanueva et al (29)	2001	Computer-generated random numbers	None	Yes	3	Sealed envelopes	Yes