Table 3.

Performance using T scores by cognitive domains for each level of cognitive impairment. Data were expressed as mean ± SD. T-score was a standard score Z shifted and scaled to have a mean of 50 and a standard deviation of 10. Higher scores are consistent with better performance on all cognitive domains.

Domains	All (n = 613)	Cognitive impairment			pa
		Non (n = 117)	Mild (n = 228)	Major (n = 268)
Memory	50.00 ± 6.46	55.21 ± 5.12b	51.63 ± 5.24b	46.33 ± 5.77b	< 0.001
Attention/processing speed	50.00 ± 8.82	57.64 ± 4.84b	53.46 ± 5.21b	43.72 ± 8.33b	< 0.001
Executive function	50.00 ± 7.21	55.71 ± 3.47b	53.10 ± 3.89b	44.87 ± 7.24b	< 0.001
Language	50.00 ± 8.13	54.29 ± 5.83b	52.53 ± 6.27b	45.98 ± 8.57b	< 0.001
Visuospatial function	50.00 ± 10.00	56.33 ± 2.19c	55.41 ± 2.83c	42.64 ± 11.11b	< 0.001

^ap value for one-way ANOVA F test, the null hypothesis is that mean values are equal for all 3 cognitive groups.

^bDesignate significant difference from any other cognitive group values in the same row (after least significant difference (LSD) adjustment for multiple comparisons).

^cDesignate nonsignificant differences in the visuospatial function domain between the non- and mild cognitive impairment groups (p = 0.288).