Table 3.

Regression results examining one predictor and one outcome independently

Predictor	Outcome	Coefficient	95% Confidence Interval
PSQI	ADLs	.05***	[.03, .07]
PSQI	Grip strength	−.24*	[−.46, −.02]
PSQI	Gait speed	.18**	[.05, .30]
PSQI	Chair stands	.11*	[.00, .23]
WASO	ADLs	.09*	[.01, .16]
WASO	Grip strength	−.43	[−1.31, .45]
WASO	Gait speed	.64*	[.09, 1.19]
WASO	Chair stands	.48	[−.03, 1.00]
Latency	ADLs	.03	[−.03, .10]
Latency	Grip strength	−.57	[−1.34, .20]
Latency	Gait speed	.15	[−.21, .51]
Latency	Chair stands	.27	[−.15, .69]
Short duration (<6 hrs.)	ADLs	−.04	[−.15, .06]
Long duration (>8 hrs.)	ADLs	.10	[−.18, .38]
Short duration (<6 hrs.)	Grip strength	−.21	[−1.71, 1.30]
Long duration (>8 hrs.)	Grip strength	−3.83	[−8.00, .33]
Short duration (<6 hrs.)	Gait speed	−.16	[−.91, .59]
Long duration (>8 hrs.)	Gait speed	−.65	[−2.14, .85]
Short duration (<6 hrs.)	Chair stands	.23	[−.48, .95]
Long duration (>8 hrs.)	Chair stands	−.28	[−1.53, .97]
Mean MP	ADLs	.03	[−.04, .10]
Mean MP	Grip strength	−.56	[−1.27, .15]
Mean MP	Gait speed	.09	[−.25, .43]
Mean MP	Chair stands	.13	[−.28, .53]
SD MP	ADLs	−.03	[−.05, .00]
SD MP	Grip strength	.36*	[.03, .68]
SD MP	Gait speed	.00	[−.17, .18]
SD MP	Chair stands	−.06	[−.26, .14]

Note. All models control for gender, age, race, disease burden, marital status, obesity, education, and the time lag between questionnaire assessments and the clinic stay. ADLs = Activities of daily living (higher values indicate more limitations); PSQI = Pittsburgh Sleep Quality Index; WASO = wake after sleep onset; MP = midpoint; SD = standard deviation. For interpretability, WASO and latency were converted to 30-minute units, and mean MP and SD MP were centered and standardized.

^***p < .001

^**p< .01

^*p<.05.