Table 1

Lifetime, one week, and point prevalence of neck, mid back, and low back pain at age 11–13 and two years later

		11-13 yr. (n = 1291)						13-15 yr. (n = 1064)
		Girls (n = 625)			Boys (n = 666)			Girls (n = 499)			Boys (n = 565)
		n (mis)	%	95% CI	n (mis)	%	95% CI	n (mis)	%	95% CI	n (mis)	%	95% CI
Lifetime prevalence	NP	491	78.6	75.3, 81.2	490	73.6	70.2, 76.9	408	81.8	78.4, 85.2	410	72.6	68.9, 76.2
	MBP	382	61.1	57.3, 64.9	387 (1)	58.2	54.4, 61.9	339	67.9	63.8, 72.0	336 (1)	59.6	55.5, 63.6
	LBP	302 (2)	48.5	44.6, 52.4	271 (1)	40.8	37.0, 44.5	293 (1)	58.8	54.5, 63.2	258 (1)	45.7	41.6, 49.9
One week prevalence	NP	149	23.8	20.5, 27.2	150	22.5	19.3, 25.7	164	32.9	28.7, 37.0	151 (2)	26.8	23.2, 30.5
	MBP	105 (1)	16.8	13.9, 19.8	132 (1)	19.8	16.8, 22.9	144 (3)	29.0	25.0, 33.0	136 (3)	24.2	20.7, 27.7
	LBP	82 (2)	13.2	10.5, 15.8	66 (1)	9.9	7.7, 12.2	108 (2)	21.7	18.1, 25.4	103 (5)	18.4	15.2, 21.6
Point prevalence	NP	68 (1)	10.9	8.5, 13.3	70 (2)	10.5	8.2, 12.9	81 (3)	16.3	13.1, 19.6	66 (4)	11.8	9.1, 14.4
	MBP	42	6.7	4.8, 8.7	62 (1)	9.3	7.1, 11.5	47 (2)	9.5	6.9, 12.0	52 (3)	9.3	6.9, 11.6
	LBP	31 (2)	5.0	3.3, 6.7	28 (1)	4.2	2.7, 5.7	40 (3)	8.1	5.7, 10.5	33 (6)	5.9	3.9, 7.9

CI = Confidence intervals; LBP = Low back pain; MBP = Mid back pain; Mis = Missing values; NP = Neck pain.