Table 2.

Meta-analysis results.

Contrast model	OR (95% CI)	P	Test for heterogeneity		Publication bias (Egger's test)		Publication bias (Begg's test)		Analysis model
			I 2 (%)	P	t	P	Z	P
C vs. T	0.981 (0.887, 1.084)	0.700	44.60	0.025	0.45	0.656	0.54	0.592	R
CC vs. TT	1.065 (0.783, 1.448)	0.689	55.30	0.004	0.35	0.733	0.68	0.499	R
CT vs. TT	0.900 (0.820, 0.987)	0.026	0.00	0.603	0.02	0.984	0.05	0.964	F
CC + CT vs. TT	0.928 (0.849, 1.014)	0.098	0.00	0.544	0.37	0.720	0.77	0.444	F
CC vs. TT + CT	1.104 (0.860, 1.416)	0.438	59.20	0.001	0.97	0.348	0.70	0.484	R

R: random effect model; F: fixed-effect model; OR: odds ratio; CI: confidence interval.