Table 3.

The dose–response between the amount of time spent participating in sports activities and the occurrence of LBP

	Group 1 (n = 7,095)	Group 2 (n = 6,720)	Group 3 (n = 5,526)
Time spent participating in sports activities (h/week)	−6.0	6.1–12.0	12.3+
Experience of a history of LBP	1,470 (20.7)	2,046 (30.4)	2,239 (40.5)
Odds ratio (95% CI)	1.00	1.13 (0.99–1.28)*	1.43 (1.26–1.64)†

The comparison between the amount of time spent participating in sports activities and the occurrence of LBP in three groups were calculated by multiple logistic regression analysis (grade, gender, and BMI corrected)

* P = 0.072, ^† P < 0.001