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. Author manuscript; available in PMC: 2017 Apr 5.
Published in final edited form as: Int J Geriatr Psychiatry. 2015 Jun 15;31(3):247–255. doi: 10.1002/gps.4318

Table 3.

Associations between sleep variables and cognitive domains. Longitudinal results

Sleep variable Language Speed of processing Executive-function Memory
Sleep disturbancea Unadjusted B = 0.001 B = −0.002 B = 0.001 B = 0.001
p = 0.375 p = 0.213 p = 0.419 p = 0.135
Adjusted B = 0.000 B = −0.001 B = 0.000 B = 0.001
p = 0.611 p = 0.210 p = 0.624 p = 0.409
Snoringa Unadjusted B = 0.001 B = 0.001 B = 0.002 B = 0.000
p = 0.704 p = 0.893 p = 0.433 p = 0.827
Adjusted B = 0.001 B = −0.001 B = 0.003 B = 0.001
p = 0.315 p = 0.673 p = 0.072 p = 0.510
Awaken short of breath/with headachea Unadjusted B = −0.003 B = −0.011 B = 0.001 B = 0.004
p = 0.294 p = 0.123 p = 0.880 p = 0.350
Adjusted B = 0.002 B = −0.010 B = 0.001 B = 0.004
p = 0.213 p = 0.109 p = 0.702 p = 0.199
Sleep adequacya Unadjusted B = 0.003 B = 0.002 B = 0.001 B = 0.002
p = 0.017 p = 0.260 p = 0.281 p = 0.082
Adjusted B = 0.001 B = 0.000 B = 0.003 B = 0.001
p = 0.053 p = 0.875 p = 946 p = 0.434
Daytime somnolencea Unadjusted B = −0.033 B = −0.045 B = −0.015 B = −0.022
p = 0.000 p = 0.001 p = 0.038 p = 0.009
Adjusted B = 0.000 B = −0.003 B = 0.001 B = 0.001
p = 0.312 p = 0.027 p = 0.139 p = 0.420

B value is for the sleep variable × time interaction. A significant value indicates different rate of decline as a function of the sleep variable.

Generalized estimating equation models before and after adjusting for ethnicity, education, age, gender, APOE-ε4, and depression.

A p value of less than 0.05 was considered statistically significant, and the corresponding results are shown in bold.

a

Sleep disturbance (included questions: “How long did it usually take for you to fall asleep during the past 4 weeks”, “Feel that your sleep was not quiet (moving restlessly, feeling tense, speaking, etc.) while sleeping”, “Have trouble falling asleep”, “Awaken during your sleep time and have trouble falling asleep again”), Snoring (“Snore during your sleep”), Awaken short of breath/with headache (“Awaken short of breath or with a head-ache”), Sleep adequacy (“Get enough sleep to feel rested upon waking in the morning”, “Get the amount of sleep you needed”), and Daytime somnolence (“Feel drowsy or sleepy during the day”, “Have trouble staying awake during the day”, “Take naps (5 min or longer) during the day”). Positive B value means the more the sleep problems increase, the better is the performance.