Table 1.

Gender- and school-grade of subjects in Scoliosis and No scoliosis groups

	Prevalence of scoliosis (%)	Scoliosis group		No scoliosis group		P value
		No.	%	No.	%
Total	0.159	51	100.0	32,083	100.0
Gender						0.002
Male	0.088	14	27.5	15,889	49.5
Female	0.228	37	72.5	16,194	50.5
School-gradea						<0.001
4th grade	0.022	1	2.0	4,518	14.1
5th grade	0.022	1	1.9	4,638	14.5
6th grade	0.156	7	13.0	4,475	13.9
1st year	0.195	12	22.2	6,152	19.2
2nd year	0.144	9	18.5	6,240	19.4
3rd year	0.345	21	19.6	6,060	18.9

^aFourth–sixth grade of elementary school and first–third year of junior high school of those pupils are 9–11 years old and 12–14 years old, respectively, at the start of the new school year