Table 1 Sample characteristics of participants at T1 (N = 2,228)

Age

77.42 (7.57)

65

103

Female

1,331 (59.74%)

0

1

Married

1,437 (64.50%)

0

1

Education

8.84 (5.00)

0

26

Income

2.03 (1.08)

1

10

Years living in the US

24.54 (12.01)

5.71

95.67

Acculturation

14.57 (3.83)

12

54

Alcohol use (amount/day)

0.02 (0.07)

0

1.02

Physical performance

5.95 (5.60)

0

20

BMI categories

 Normal

1,585 (71.36%)

1

3

 Overweight

553 (24.90%)

 Obese

83 (3.74%)

Depressive symptoms

1.50 (2.78)

0

22

IADLs*

6.42 (7.85)

0

36

Daytime sleepiness

1

5

 Never

1,064 (47.78%)

 Rarely

299 (13.43%)

 Sometimes

468 (21.01%)

 Often

253 (11.36%)

Almost always

143 (6.42%)

Overall sleep quality (PSQI)

4.13 (3.05)

0

12

Subjective sleep quality

0

3

 Very good

226 (11.94%)

 Fairly good

1,101 (49.42%)

 Fairly bad

673 (30.21%)

 Very bad

188 (8.44%)

Sleep latency

0

3

 ≤ 15 min

875 (39.27%)

 > 15 to ≤ 30 min

691 (31.01%)

 > 30 to ≤ 60 min

405 (18.18%)

 > 60 min

257 (11.54%)

Sleep efficiency

0

3

 ≥ 85%

1,347 (60.76%)

 ≥ 75% to < 85%

346 (15.61%)

 ≥ 65% to < 75%

212 (9.56%)

 < 65%

312 (14.07%)

Sleep duration

0

3

 >=7 h

1,058 (47.64%)

 < 7 to > = 6 h

489 (22.02%)

 < 6 to > = 5 h

354 (15.94%)

 < 5 h

320 (14.41%)

Insomnia symptoms

5.50 (4.24)

0

16

Global cognition

-0.37 (0.95)

-3.12

1.63

Perceptual speed

-0.42 (1.03)

-2.36

3.16

Episodic memory

-0.36 (1.09)

-2.85

1.29

Working memory

-0.20 (0.95)

-2.15

2.94

C_MMSE

-0.50 (1.37)

-5.72

1.02