Table 2

Comparison of single, composite antioxidant between AD patients and control group.

	Study or Sub group			Control			Weight	Mean Difference
	Mean	SD	Total	Mean	SD	Total		IV, Random, 95% CI
^*Single antioxidant
Arlt 2012	-2.1	3.7	12	-1.6	2.5	11	4.4%	-0.50 [-3.06,2.06]
De Waal 2014	25.1	2.9	86	25.4	2.7	93	43.0%	-0.30 [-1.12,0.52]
Dysken 2014	-0.95	3.65	115	-1.39	3.6	106	31.8%	0.44 [-0.52,1.40]
Galasko 2012	-1	2.5	25	-0.9	2.5	25	15.2%	-0.10 [-1.49,1.29]
Ringman 2012	-1.89	2.6	9	-0.45	2.6	11	5.6%	-1.44 [-3.73,0.85]
Total (95% CI)			247			246	100%	-0.11 [-0.65,0.43]
^**Composite antioxidant
Galasko 2012	-2.8	2.9	28	-0.9	2.5	25	53.1%	-1.90 [-3.35,-0.45]
Shinto 2014	-1	2.42	12	-4.6	4.64	11	46.9%	3.60 [0.54,6.66]
Total (95% CI)			40			36	100%	0.68 [-4.70,6.06]

↵* Heterogeneity: Tau²=0.00; Chi²=2.86, df=4 (p=0.58); I²=0% Test for overall effect: Z=0.39 (p=0.70)
↵** Heterogeneity: Tau²=13.63; Chi²=10.10, df=1 (p=0.001); I²=90%Test for overall effect: Z=0.25 (p=0.80)