Table 2.

Incidence Rates (per 100 Person-Years) and Hazard Ratios From Cox Regression Analyses: All Dementia and Subtypes of Dementia Comparing G biloba With Placebo for All Participants and Those Classified at Baseline With Normal Cognition and Mild Cognitive Impairment

	All Participants (N = 3069)				Baseline Normal Cognition (n = 2587)				Baseline MCI (n = 482)
	Rate (No. of Events)				Rate (No. of Events)				Rate (No. of Events)
Outcome	Placebo (n = 1524)	G biloba (n = 1545)	HR (95% CI)	P Value	Placebo (n = 1298)	G biloba (n = 1289)	HR (95% CI)	P Value	Placebo (n = 226)	G biloba (n = 256)	HR (95% CI)	P Value
All dementia	2.94 (246)	3.27 (277)	1.12 (0.94–1.33)	.21	2.16 (159)	2.25 (165)	1.05 (0.84–1.30)	.67	8.68 (87)	9.82 (112)	1.13 (0.85–1.50)	.39
Alzheimer without vascular dementiaa	1.92 (161)	2.27 (192)	1.18 (0.97–1.46)	.11	1.36 (100)	1.53 (112)	1.13 (0.86–1.48)	.36	6.09 (61)	7.02 (80)	1.15 (0.83–1.61)	.40
Alzheimer with vascular dementiab	0.71 (59)	0.77 (65)	1.09 (0.77–1.55)	.63	5.02 (37)	5.60 (41)	1.12 (0.72–1.74)	.63	2.20 (22)	2.10 (24)	0.96 (0.54–1.71)	.89
Total Alzheimer dementia	2.63 (220)	3.04 (257)	1.16 (0.97–1.39)	.11	1.86 (137)	2.09 (153)	1.13 (0.90–1.42)	.30	8.28 (83)	9.12 (104)	1.10 (0.83–1.47)	.51
Vascular dementia without Alzheimer dementia	0.20 (17)	0.08 (7)	0.41 (0.17–0.98)	.05	0.19 (14)	0.07 (5)	0.36 (0.13–1.00)	.05	0.30 (3)	0.18 (2)	0.59 (0.10–3.51)	.56

Abbreviations: CI, confidence interval; G biloba, Ginkgo biloba; HR, hazard ratio; MCI, mild cognitive impairment.

^aMeeting NINCDS (National Institute of Neurological and Communication Disorders and Stroke) criteria for probable or possible Alzheimer disease without vascular dementia.

^bMeeting ADDTC criteria (Alzheimer’s Disease Diagnostic and Treatment Centers) for probable or possible vascular dementia.