Table 2.

Meta-Analysis of Case-Control Studies of the Association between the OPRM1 Asn40Asp Polymorphism and Opioid Dependence

Study	Case Asp Frequency	Control Asp Frequency	OR	95% CI
Bart et al. 2004	0.31	0.15	2.30	1.37 - 3.88
Bergen et al. 2004	0.14	0.31	0.43	0.12 - 1.46
Bond et al. 1998 (African)	0.04	0.00	1.09	0.04 - 28.1
Bond et al. 1998 (European)	0.23	0.23	1.03	0.30 - 3.49
Bond et al. 1998 (Hispanic)	0.21	0.78	0.18	0.06 - 0.56
Crowley et al. 2003 (European)	0.31	0.31	1.01	0.61 - 1.68
Crowley et al. 2003 (African)	0.09	0.10	0.92	0.37 - 2.32
Drakenberg et al. 2006	0.31	0.12	2.97	0.79 - 11.1
Franke et al. 2001	0.26	0.24	1.11	0.80 - 1.55
Gelernter et al. 1999 (European)	0.25	0.31	0.78	0.38 - 1.63
Gelernter et al. 1999 (African)	0.00	0.09	0.24	0.01 - 4.44
Gelernter et al. 1999 (Hispanic)	0.25	0.28	0.89	0.23 - 3.35
Li et al. 2000	0.69	0.60	1.22	0.92 - 1.63
Luo et al. 2003 (European)	0.20	0.27	0.70	0.16 - 3.11
Luo et al. 2003 (African)	0.20	0.05	3.96	0.37 - 42.1
Shi et al. 2002	0.50	0.54	0.91	0.53 - 1.52
Szeto et al. 2001	0.79	0.59	1.57	1.09 - 2.27
Tan et al. 2003 (Indian)	0.50	0.95	0.37	0.17 - 0.79
Tan et al. 2003 (Malaysian)	0.84	0.90	0.88	0.48 - 1.63
Tan et al. 2003 (Asian)	0.60	0.74	0.73	0.45 - 1.17
Zhang et al. 2006	0.26	0.25	1.04	0.64 - 1.69
Pooled	0.33	0.39	0.98	0.78 - 1.21