Exposure to second-hand smoke during early life and subsequent sleep problems in children: a population-based cross-sectional study

Table 4 Associations of SHS exposure during early life with the T-scores of DOES and SHY stratified by sex or by child age^a

	Exposure to SHS during early life			P _interaction
	Unexposed	Ever exposed during pregnancy or the first 2 years of life	Ever exposed during both pregnancy and the first 2 years of life	P _interaction
Stratified by sex
DOES t-score				0.0298
Males	[1] Reference	1.82 (1.40, 2.24)	2.89 (2.50, 3.27)
Females	[1] Reference	2.32 (1.90, 2.74)	3.50 (3.13, 3.88)
SHY t-score				0.0253
Males	[1] Reference	1.58 (1.18, 1.97)	2.33 (1.97, 2.69)
Females	[1] Reference	0.91 (0.51, 1.30)	1.92 (1.57, 2.26)
Stratified by child age
DOES t-score				< 0.001
6–11 years (primary school)	[1] Reference	1.61 (1.19, 2.04)	2.97 (2.58, 3.36)
12–14 years (middle school)	[1] Reference	2.49 (2.04, 2.95)	4.69 (3.44, 5.94)
15–18 years (high school)	[1] Reference	1.98 (1.32, 2.65)	4.65 (3.68, 5.63)

Abbreviations: CI Confidence interval, DOES Disorders of excessive somnolence, SHS Second-hand smoke, SHY Sleep hyperhidrosis
^aModel was adjusted for a school-level random intercept, child age, sex, only child, preterm birth and low birth weight, parental educational levels, yearly household income, maternal age during pregnancy, maternal smoking and alcohol consumption during pregnancy and interaction term between SHS exposure and sex/child age

ISSN: 1476-069X