Table 2.

Unadjusted mean differences of cognitive function during 2 years in 2017-Group and 2018-Group (intergroup comparison).

	2017-Group									2018-Group									Cohen’s d	p-Value *
	2017 Year			2019 Year			Mean Diff. (2019–2017)			2018 Year			2020 Year			Mean Diff. (2020–2018)
	n	Mean	SD	n	Mean	SD	n	Mean	SD	n	Mean	SD	n	Mean	SD	n	Mean	SD
MMSE	1027	25.67	3.13	1027	25.39	3.31	1027	−0.28	2.57	879	25.59	3.19	879	25.23	3.59	879	−0.36	2.34	−0.0334	0.4640
Word List Memory	1027	16.66	4.26	1025	17.20	4.49	1025	0.53	3.25	874	17.74	4.40	877	17.59	4.56	873	−0.14	3.56	−0.1963	<0.0001
Word List Recall	1027	5.51	2.08	1024	5.55	2.21	1024	0.03	1.64	873	5.81	2.10	877	5.56	2.24	872	−0.25	1.67	−0.1712	0.0002
Word List Recognition	1026	8.64	1.73	1026	8.62	1.83	1025	−0.01	1.60	873	8.70	1.75	877	8.57	1.95	872	−0.13	1.59	−0.0773	0.0937
TMT	1014	76.30	51.44	1004	76.67	51.54	1001	1.64	34.13	848	81.75	54.09	849	82.53	54.48	832	1.33	33.78	−0.0089	0.8501
7-Digit span	1026	10.47	3.72	1026	10.12	3.68	1025	−0.35	2.58	876	9.54	3.57	877	9.29	3.59	875	−0.26	2.38	0.0367	0.4218
FAB	1026	13.65	2.90	1027	13.67	3.01	1026	0.02	2.49	876	13.10	3.14	877	13.33	3.23	875	0.23	2.43	0.0852	0.0644

Statistical significance was set at p < 0.05. p-values were based on the independent t test for the difference (*); the effect size of Cohen’s d for two groups is (Mean diff. (2020–2018)—Mean diff. (2019–2017))/SD_pooled; MMSE: mini-mental state examination; recall test (total score of 10); recognition test (total score of 10); TMT (Trail-Making Test, out of 360 s, increasingly worse); Span (Digit span test, total score of 28); FAB: Frontal Assessment Battery (total score of 18).