Prevalence of Insomnia Among Patients with Bronchial Asthma

Figures & data

Table 1 Baseline Characteristics in Patients with Different Levels of Asthma Control

Characteristic	All (n=200)	Insomnia (n=93)	No Insomnia (n=107)	P value
Age (years)	51 ± 17	54 ± 16	47 ± 17	0.18
Female	135 (67)	68 (73)	67 (63)	0.11
Married	146 (73)	67 (72)	79 (74)	0.78
Educated^‡	176 (88)	80 (86)	96 (90)	0.42
BMI (kg/m^2)*	31 (9.6)	32 (10)	29 (8.8)	0.50
Ever smoked	7 (3)	3 (3)	4 (4)	0.84
Coffee/tea intake	3.0 ± 3.0 / 2.0 ± 1.8	3.6 ± 3.6 / 2.0 ± 1.9	2.6 ± 2.7 / 1.8 ± 1.7	0.18/ 0.15
Sleep duration, hours*	6 (2)	5 (3)	6 (2)	0.01
Comorbid conditions
Allergic rhinitis	96 (48)	43 (46)	53 (50)	0.64
GERD	38 (19)	12 (13)	26 (24)	0.04
Diabetes mellitus	71 (35)	35 (38)	36 (34)	0.56
Hypertension	90 (45)	51 (55)	39 (36)	0.01
Asthma control test score	17 ± 4.9	15 ± 4.4	19 ± 4.5	0.001
FEV1, % predicted	76 ± 19.3	83 ± 23.2	77 ± 22.7	0.32
FVC, % predicted	82 ± 22.6	83 ± 22.7	82 ± 20.7	0.34
FEV1/FVC, % predicted	77 ± 15.7	79 ± 12.9	77 ± 15.6	0.45
ISI score	10 ± 7.2	16 ± 4.5	4±2.9	0.001

Notes: Data were expressed as mean ± standard deviation or as a number (percentage) unless otherwise specified. *Median (interquartile range). ^‡Educated: achieved more than primary school.

Abbreviations: BMI, body mass index; GERD, gastroesophageal reflux disease; ISI, Insomnia Severity Index.

Table 2 Insomnia Severity Index Comparisons According to Level of Asthma Control

	Asthma Control
	Well-Controlled (n=67)	Partially Controlled (n=55)	Uncontrolled (n=78)	P value
Total ISI score, median (IQR)	2 (6)	9 (10)	12 (9)	<0.001
Insomnia, ISI ≥10	13 (19%)	27 (49%)	53 (68%)	<0.001
Insomnia severity
No insomnia (ISI = 0–7)	52 (78%)	23 (42%)	15 (19%)	<0.001
Sub-threshold insomnia (ISI = 8–14)	7 (10%)	18 (33%)	30 (38%)
Moderate insomnia (ISI = 15–21)	7 (10%)	10 (18%)	24 (31%)
Severe insomnia (ISI = 22–28)	1 (2%)	4 (7%)	9 (12%)

Abbreviations: IQR, interquartile range; ISI, Insomnia Severity Index.

Table 3 Factors Associated with the Presence of Insomnia

	Odds Ratio	95% CI	P value
Age (years)	1.02	1.00–1.05	0.04
Female	1.55	0.72–3.36	0.26
Married	0.70	0.33–1.50	0.37
Educated^‡	1.05	0.37–2.97	0.93
Ever smoked	1.61	0.27–9.55	0.60
Coffee/tea intake	0.57	0.17–1.95	0.37
BMI ≥30 kg/m^2	3.32	1.15–9.62	0.03
Allergic rhinitis	1.01	0.52–1.97	0.97
GERD	0.41	0.17–0.96	0.04
Partially controlled asthma	8.45	3.68–19.39	0.001
Uncontrolled asthma	3.59	1.49–8.64	0.004

Note: ^‡Educated: achieved more than primary school.

Abbreviations: BMI, body mass index; CI, confidence interval; GERD, gastroesophageal reflux disease.