Table 3. Demographic and physical leisure activity variables and risk of LBP using univariate logistic regression .

	% With LBP	OR	95% CI	P
Age (y)
≤13	35	1.0	(Referent)
>13	34	1.05	(0.86–1.30)	0.621
Gender
Boy	29	1.0	(Referent)
Girl	39	1.57	(1.28–1.94)	0.001
BMI (kg/m2)
<17.33	31	1.0	(Referent)
17.33–19.38	34	1.15	(0.84–1.56)	0.362
19.39–22.04	36	1.25	(0.92–1.70)	0.140
>22.04	34	1.16	(0.85–1.58)	0.322
Family member with back pain
No	33	1.0	(Referent)
Yes	40	1.83	(1.48–2.27)	0.001
Playing sport (h/wk)
<1	37	1.0	(Referent)
1–3	33	0.83	(0.65–1.07)	0.150
>3	33	0.84	(0.65–1.08)	0.170
Using a computer (h/wk)
<1	34	1.0	(Referent)
1–4	35	1.05	(0.83–1.35)	0.680
>4	34	1.03	(0.80–1.34)	0.820
Playing games (h/wk)
<1	34	1.0	(Referent)
1–2	38	1.2	(0.92–1.55)	0.180
>2	33	0.96	(0.75–1.22)	0.710
Watching TV (h/wk)
<3	33	1.0	(Referent)
3–12	33	1.02	(0.79–1.31)	0.900
>12	37	1.17	(0.91–1.50)	0.216
Part time job
No	34	1.0	(Referent)
Yes	35	1.05	(0.57–1.91)	0.880

Abbreviations: LBP, low back pain; BMI, body mass index; OR, odds ratio.