School environment factors were associated with BMI among adolescents in Xi'an City, China

BMC Public Health

Table 2 BMI of and school environment factors in Xi'an City

School Factors		School No. or mean (SD)	Student No.	BMI (SD)	Unadjusted		Adjusted ^*
					Coef^**	95% CI	Coef**	95% CI
Playground per person (10 m ² )		0.5 (0.4)***	N/A	N/A	-0.5	-1.2, 0.3	-0.2	-0.9, 0.4
School oval	Yes	27	1619	20.0 (3.4)	Reference
	No	3	173	19.3 (3.1)	-0.6	-1.6, 0.3	-0.6	-1.4, 0.2
Morning exercise	Yes	23	1379	19.9 (3.4)	Reference
	No	7	413	20.1 (3.3)	0.3	-0.5, 1.0	0.1	-0.6, 0.7
Class recess exercise	Yes	28	1673	19.9 (3.4)	Reference
	No	2	119	20.2 (2.9)	0.3	-1.0, 1.5	-0.2	-1.8, 0.9
Sports meetings	twice a year	13	779	19.7 (3.2)	Reference
	Once a year	15	893	19.8 (3.3)	0.1	-0.4, 0.6	0.1	-0.3, 1.6
	Once in 2 years	2	120	22.0 (4.0)	2.2	1.2, 3.2	1.9	1.0, 2.8
Health education	Yes	27	1614	19.8 (3.3)	Reference
	No	3	178	21.4 (3.9)	1.6	0.7, 2.4	1.2	0.4, 2.0
Soft drinks at school shops	No	2	181	19.8 (3.2)	Reference
	yes	8	1619	21.2 (4.1)	1.4	0.5, 2.3	1.2	0.4, 2.0
Fast food outlets	No	21	1259	19.7 (3.8)	Reference
	Yes	9	541	20.5 (3.1)	0.8	0.2, 1.5	0.7	0.1, 1.2
Number Fast food outlets	0	16	954	19.2 (3.0)	Reference
	1	8	477	20.3 (3.5)	0.8	0.1, 1.4	0.6	-.0.02, 1.1
	≥2	6	361	20.5 (3.9)	1.0	0.3, 1.7	0.8	0.1, 1.4
Bike riding (allowed)	Yes	29	1740	20.0 (3.4)	Reference
	No	1	60	18.7 (2.4)	-1.2	-2.9, 0.4	-0.8	-2.2, 0.6

* Adjusted for significant socio-demographic factors including age, parental education, parental BMI, and household wealth Index.
**coefficient of school factors was from linear mixed effect models
*** mean playground per person in 10 m² with the standard deviation.

ISSN: 1471-2458