Table 2. pooled HDV Risk Factors Among HBsAg positive patients in Iran, 1983-2008.

	Study (Investigation Year)	OR	95% CI	Weighting Score	Pooled Estimation (95% CI)
Blood transfusion					1.1 (0.40- 2.98)
	Alizadeh et al. (2002-2007) [21]	0.43	0.05-3.73	0.84
	Taghavi et al. (2003-2004) [45]	0.62	0.07-5.4	0.83
	Alavian et al. (2001-2004) [19]	2.4	0.64-9.1	2.18
HBeAg positive					1.26 (0.66-2.4)
	Ataei et al. (2009) [24]	0.72	0.15-3.4	1.56
	Alizadeh et al. (2002-2007) [21]	2.2	0.66-7.22	2.70
	Hassanjani Roshan et al. (2000-2002) [34]	5.1	1.47-18.33	2.42
	Rezvan et al. (1986-1988) [39]	0.83	0.025-0.27	2.67
	Amini Kafi-abad et al. (2000) [22]	0
IDU					1.6 (0.78- 3.214)
	Taghavi et al. (2003-2004) [45]	5.92	1.36-25.78	1.77
	Jedari Seifi et al. (2006-2007) [41]	2.45	1- 6.03	4.75
	Alizadeh et al. (2002-2007) [21]	2.06	0.35 - 11.92	1.25
Hemodialysis					1.72 (0.79- 3.76)
	Karimi et al. (2000) [35]	24.79	5.56 -110.48	1.72
	Jedari Seifi et al. (2006-07) [41]	1.7	0.68- 4.23	4.61
	Taghavi et al. (2003-2004) [45]	0