Table 1.

Demographic variables and clinical information for the AD-nSI and AD-SI groups

	AD-nSI group (n = 31)	AD-SI group (n = 19)	P-value
Male	18(58)	10(53)	0.707
Age (yr)	63.19±10.09	61.58±8.54	0.564
Age of onset (yr)	51.96±23.55	59.65±9.18	0.131
Disease duration (yr)	3.00 (1.00, 5.00)	2.00 (1.08, 3.75)	0.76
Educational level			0.695
Primary school and below	6(19)	4(21)
Middle and high school	17(55)	12(63)
Bachelor’s degree and above	8(26)	3(16)

Sex is expressed as number (percentage), and was analyzed by independent-sample t-test. Age and age of disease onset are expressed as mean ± SD, and were analyzed by independent-sample t-test. Disease durations are expressed as median (first quartile, third quartile), and were analyzed by Mann-Whitney U test. Educational levels are expressed as number (percentage), and were analyzed by Chi-squared test. AD-nSI: Alzheimer’s disease with no sleep insufficiency; AD-SI: Alzheimer’s disease with sleep insufficiency.