Table 2.

Characteristics of the studies included in the meta-analysis.

Study* (ref.)	NCT/FDA-reference	Add-on to	Description of randomization	Description of allocation	Description of blinding	Reporting of drop-out	Intention-to-treat
Albiglutide versus placebo
Rosenstock et al. [19]	NCT00518115	None/Metf.	NA	NA	A	A	Yes
Exenatide versus placebo
Gill et al. [20]	NCT00516074	Metf./TZD	NA	NA	A	A	Yes
Kadowaki et al. [21]	NCT00382239	Sulfonylurea	A	NA	A	A	Yes
Zinman et al. [22]	NCT00099320	TZD	A	A	A	A	Yes
Gao et al. [23]	NCT00324363	SU + Metf.	A	NA	A	A	Yes
DeFronzo et al. [24]	NCT00135330	Rosiglitazone	A	NA	OL	A	Yes
Apovian et al. [25]	NR	Multiple	A	A	A	A	Yes
Moretto et al. [26]	NCT00381342	None	A	A	A	A	Yes
Liutkus et al. [27]	NR	Metf/TZD + Met	A	A	A	A	Yes
DeFronzo et al. [28]	NCT00039013	Metformin	A	NA	A	A	Yes
Buse et al. [29]	NCT00039026	Sulfonylurea	A	NA	A	A	Yes
Kendall et al. [30]	NCT00035984	SU + Metf.	NA	NA	A	A	Yes
Exenatide versus rosiglitazone
DeFronzo#et al. [24]	NCT00135330	None	A	NA	OL	A	Yes
Exenatide versus glibenclamide
Derosa et al. [31]	NCT00135330	None	A	NA	OL	A	Yes
Exenatide versus BiAsp 30/70
Bergenstal et al. [32]	NCT00097877	SU + Metf.	A	A	OL	A	Yes
Nauck et al. [33]	NCT00082407	SU + Metf.	A	A	OL	A	Yes
Exenatide versus glargine
Barnett et al. [34]	NCT00099619	SU + Metf.	A	A	OL	A	Yes
NCT00360334 [35]	NCT00360334	OAD	NR	NR	OL	A	Yes
Heine et al. [36]	NCT00082381	SU + Metf.	A	A	OL	A	Yes
Bunck et al. [37]	NCT00097500	Metformin	A	NA	OL	A	Yes
Diamant et al. [38]	NCT00641056	SU + Metf./Metf	A	A	OL	A	Yes
Exenatide versus insulin
Davis et al. [39]	NCT00099333	SU/Metf.	NA	NA	OL	A	Yes
Exenatide LAR versus placebo
Kim et al. [40]	NCT00103935	Metf./None	A	A	A	A	Yes
Exenatide LAR versus pioglitazone
Bergenstal et al. [41]	NCT00637273	None	A	A	A	A	Yes
Exenatide LAR versus sitagliptin
Bergenstal et al. [41]#	NCT00637273	None	A	A	A	A	Yes
Liraglutide versus placebo
Madsbad et al. [42]	FDA_1310	None	NA	NA	A	A	Yes
Vilsbøll [43]	NCT00154401	None	NA	NA	A	A	Yes
Seino et al. [44]	FDA_1334	None	A	A	A	A	Yes
Kaku et al. [45]	NCT00395746	Sulfonylurea	NA	NA	NA	NA	Yes
Russell-Jones et al. [46]	NCT00331851	SU + Metf.	A	A	A	A	Yes
Zinman et al. [47]	NCT00333151	Metf. + TZD	A	A	A	A	Yes
Marre et al. [48]	NCT00318422	Sulfonylurea	NA	NA	A	A	Yes
Nauck et al. [49]	NCT00318461	Metformin	A	A	A	A	Yes
Liraglutide versus metformin
Feinglos et al. [50]	NR	None	NA	NA	NA	A	No
Liraglutide versus rosiglitazone
Marre#et al. [48]	NCT00318422	Sulfonylurea	NA	NA	A	A	Yes
Liraglutide versus glimepiride
Madsbad#et al. [42]	NR	None	NA	NA	OL	A	Yes
NCT00614120 [35]	NCT00614120	Metformin	NR	NR	OL	NR	NR
Nauck#et al. [49]	NCT00318461	Metformin	A	A	OL	A	Yes
Garber et al. [51]	NCT00294723	None	A	A	OL	A	Yes
Liraglutide versus glibenclamide
NCT00393718 [35]	NCT00393718	None	NR	NR	OL	NR	NR
Liraglutide versus sitagliptin
Pratley et al. [52]	NCT00700817	None	A	A	OL	A	Yes
Liraglutide versus glargine
Russell-Jones#et al. [46]	NCT00331851	SU + Metf.	A	A	A	A	Yes

*All the studies are multicenter and designed as parallel series, with the exception of NCT00099619 which is a cross-over trial; ^#studies with multiple comparators. Metf.: metformin; NA: not adequate or not adequately reported; A: adequate; TZD: thiazolidinediones; TZD + Met.: thiazolidinediones + metformin; SU + Metf.: sulfonylureas and metformin; OL: open-label; OAD: oral antidiabetic drugs; NR: not reported; SU/Metf: sulfonylureas or metformin; LAR: long-acting release.