Gastrointestinal adverse effects of varenicline at maintenance dose: a meta-analysis

Table 1 Summary of the 12 studies included for meta-analysis

Study	Total Sample Size(n)	Adverse effects^¥	Mean Age	% Male	Trial Duration with 1 mg BID dose(Weeks)	Size of Trial group	Size of Control Group	Cochrane risk of bias assessment^§
								P	Q	R	S	T	U	Overall score
Gonzales et al (2006) ³²	696	A, B, C	42.55	52.05	12	352	344	1	1	1	1	1	1	6/6
Jorenby et al(2006) ²⁹	685	A, B, C	43.45	56.65	12	344	341	1	1	1	1	1	0	5/6
Oncken et al(2006) ²⁷	259	A, B, C	41.1	50.2	12	130	129	1	1	1	1	0	0	4/6
Nides et al(2006) ²⁵	248	A, B	41.7	51.2	6	125	123	1	1	0	1	1	0	4/6
Nakamura et al(2007) ³⁰	310	A, B	40	77.6	12	156	154	1	1	1	1	1	1	6/6
Tsai et al(2007) ²⁸	250	A, B	40.3	88.8	12	126	124	1	1	0	1	1	0	4/6
Williams et al(2007) ²⁶	377	A, B, C	47.7	48.6	52	251	126	1	1	0	1	1	0	4/6
Niaura et al(2008) ³⁴	312	A	41.8	51.9	12	157	155	1	1	1	1	1	0	5/6
Wang et al(2009) ³³	333	A	38.7	96.7	12	165	168	1	1	0	1	1	0	4/6
Rigotti et al(2010) ³¹	714	A, B	56.45	78.7	12	355	359	1	1	0	1	1	1	5/6
Fagerstrom et al(2010) ⁸	431	A	43.9	89.3	12	213	218	1	1	1	1	1	1	6/6
Tashkin et al(2010) ²⁴	499	A, C	57.2	62.3	12	248	251	1	1	0	1	1	0	4/6

^¥A = Nausea, B = Constipation, C-Flatulence
^#Denote use of 1-week low-dose titration treatment
^§Cochrane risk of bias assessment: P = Allocation sequence adequately generated?; Q = Allocation adequately concealed?; R = Knowledge of allocated intervention adequately concealed?; S = incomplete outcome data adequately addressed?; T = Reports free of selective outcome reporting?; U = study free of other factors leading to high risk of bias?; 1 = item positive; 0 = negative or unknown.