Why Do They Fall? The Impact of Insomnia on Gait of Older Adults: A Case–Control Study

Figures & data

Table 1 Demographic and Sleep Characteristics

Demographic Characteristics	No-Insomnia (n=34)	Insomnia (n=39)	t/χ2 (df)	p	Effect Size
Age (years)	M=72	M=74	1.65 (71)	0.101	–
	SD= 6	SD= 6
Years of education	M=14	M=16	1.79 (65)	0.076	–
	SD=3	SD=3
% of females	62 (n=21)	72 (n=28)	0.82 (1)	0.362	–
% use of sleep medicine	12 (n=4)	38 (n=14)	6.36 (1)	0.011	0.299
Sleep Measures			U (Z)	p	Effect size
Sleep Efficiency (%)	Med= 93	Med= 79	114 (−6.07)	<0.001	0.505
	IQR= 6	IQR= 9
Sleep Latency (min)	Med= 9	Med= 17	315 (−3.84)	<0.001	0.203
	IQR= 7	IQR= 17
WASO (min)	Med= 15	Med= 45	173 (−5.41)	<0.001	0.402
	IQR= 17	IQR= 31
Sleep Duration (min)	Med= 404	Med= 408	631 (−0.35)	0.723	–
	IQR= 76	IQR= 85

Notes: A comparison of demographic and sleep characteristics between groups. Effect size are phi (φ) for Pearson’s chi-squared tests and eta-squared (η²) for Mann–Whitney U-tests.

Abbreviations: WASO, wake after sleep onset; M, mean; SD, standard deviation; Med, Median; IQR, interquartile range.

Table 2 A Comparison Between ST and DT Gait and Cognition

Gait Speed (meter/second)	No-Insomnia (n=34)	Insomnia (n=39)	t (df)/U (Z)	p	Effect Size
ST	M=1.2 SD=0.1	M=1 SD=0.2	−4.72 (62.83)	<0.001	1.07
DT	M=1.1 SD=0.2	M=0.7 SD=0.2	−6.64 (71)	<0.001	1.55
DTC (%)	Med=7	Med=18	321.5 (−3.77)	<0.001	0.195
	IQR=10	IQR=21
Cognition (Number of correct responses)			t (df)/U (Z)	p	Effect size
ST	M=27 SD=11	M=21 SD=7	−2.69 (55.99)	0.009	0.64
DT	M=23 SD=9	M=19 SD=7	−2.49 (71)	0.015	0.58
DTC(%)	Med=14	Med=15	615.5 (−0.52)	0.599
	IQR=39	IQR=41

Note: Effect size are hedge’s g for t-tests and eta-squared for Mann–Whitney U-test.

Abbreviations: ST, single task; DT, dual task; M, mean; SD, standard deviation; Med, median; IQR, interquartile range, DTC; dual task cost.

Figure 1 (A) Comparisons between the insomnia and no-insomnia groups in single-task (ST) and dual-task (DT) gait speed performance. (B) Comparisons between the insomnia and no-insomnia groups in single-task (ST) and dual-task (DT) cognitive (number of correct responses) performance. (C) Dual-task cost (DTC), for gait speed and number of correct responses in the cognitive subtraction task. *p<0.05, **p<0.01, ***p<0.001. Error bars show standard error.

Figure 2 A theoretical model proposing underlying potential mechanisms explaining the link between sleep quality, executive function, and gait quality.