Table 1.

Summary of the characteristics of the study participants

Category	n (%)	Caries n (%)	P value*	Pain n (%)	P value*	dmft (mean±SD)	P value*
Gender			<0.001		<0.001		<0.001
Male	20 245 (50.2)	12 598 (62.7)		5078 (26.2)		3.39±0.03
Female	20 115 (49.8)	12 545 (62.4)		5340 (27.7)		3.31±0.03
Age (years)			<0.001		<0.001		<0.001
3	12 390 (30.7)	6292 (50.8)		2024 (17.1)		2.28±0.03
4	13 978 (34.6)	8895 (63.6)		3420 (25.5)		3.40±0.04
5	13 992 (34.7)	10 056 (71.9)		4974 (37.0)		4.24±0.04
Ethnic			<0.001		<0.001		<0.001
Han	36 087 (89.4)	22 401 (62.1)		9231 (26.7)		3.32±0.02
Other ethnics	4273 (10.6)	2842 (66.5)		1187 (28.9)		3.63±0.06
Place of residence			<0.001		<0.001		<0.001
Urban	20 490 (50.8)	12 449 (60.8)		5166 (26.2)		3.14±0.03
Rural	19 870 (49.2)	12 794 (64.4)		5252 (27.7)		3.57±0.03
Region			<0.001		<0.001		<0.001
East	14 127 (35.0)	9385 (66.4)		3872 (28.5)		3.83±0.04
Middle	10 403 (25.8)	6216 (59.8)		2654 (27.0)		3.09±0.04
West	15 830 (39.2)	9642 (60.90		3892 (25.5)		3.09±0.03
Parents-reported child general health			<0.001		<0.001		<0.001
Good or better	28 885 (71.6)	17 860 (61.8)		6954 (25.0)		3.25±0.02
Fair or less	11 475 (28.4)	7383 (64.3)		3464 (32.0)		3.60±0.04
Parental education			<0.001		0.137		<0.001
High	12 615 (36.1*)	7326 (58.1*)		3208 (26.3*)		2.90±0.04*
Middle	9457 (23.2*)	5914 (62.5*)		2445 (26.9*)		3.34±0.04*
Low	18 278 (40.7*)	11 998 (65.6*)		4762 (27.4*)		3.66±0.03*
Household income			<0.001		0.011		<0.001
Highest	4431 (17.7*)	1942 (59.2*)		753 (25.2*)		3.01±0.06*
High	4319 (21.7*)	3037 (62.1*)		1233 (27.1*)		3.37±0.05*
Middle	5509 (20.9*)	3256 (61.6*)		1326 (27.0*)		3.27±0.05*
Low	4972 (26.2*)	4638 (63.9*)		1812 (27.1*)		3.48±0.04*
Lowest	6619 (13.6*)	2825 (65.1*)		1131 (28.2*)		3.53±0.06*

*Proportions and p values are presented after multiple imputation for parental education and household income.

dmft, decayed, missing and filling teeth.