Table 2.

Percentage of individuals identified as meeting criteria for MCI based upon Litvan et al. Level I criteria using <1.5 SD on two or more tests

Impaired %				Impaired %
	Published Norms	Internal HC Overall Group-Based Norms	Relative Risk of MCI diagnosis	Published Norms	Internal HC Age-Based Norms	Relative Risk of MCI diagnosis
Baseline	8.3%	17.7%	2.13	8.3%	13.51%	1.63
12-month	9.8%	18.0%	1.84	9.8%	17.21%	1.76
24-month	12.9%	24.7%	1.91	12.9%	18.96%	1.47
36-month	13.3%	20.4%	1.53	13.3%	20.56%	1.55

Notes: MCI = Mild Cognitive Impairment; HC = Healthy Control; ; Internally Normed z-scores were derived from the mean of the participant score minus the group mean of the healthy control group, divided by the standard deviation of the group mean of the healthy control group for each measure. The HC Overall Group Norms are based on the mean and standard deviation of the entire HC sample. The HC Age-Based Norms utilized norms from the following age ranges: 30–45, 46–60, 61–75, and 76–90.