Table 3.

Bivariate analysis of low back pain with electronic devices in high school adolescents.

Factors	Low back pain
	n	%	PR (95% CI)
Watch TV
No	79	10.4	1.00
Yes	681	89.6	1.14 (0.95–1.36)
How many times TV/week
Up to 2 times	174	22.9	1.00
3 times or more	507	66.7	1.02 (0.90–1.16)
Number of hours of TV/day
Up to 2 h	345	45.4	1.00
Above 3 h	336	44.2	1.09 (0.98–1.21)
Use of PC/videogame
No	612	80.5	1.00
Yes	148	19.5	0.99 (0.87–1.3)
Type of computer
Desktop	243	32.0	1.00
Laptop	304	40.0	1.18 (1.04–1.34)a
Desktop and laptop	65	8.6	0.91 (0.74–1.11)
Height of the computer screen
Below the midpoint	138	18.2	1.00
At the midpoint	416	54.7	0.89 (0.77–1.02)
Below the midpoint	58	7.6	0.84 (0.67–1.06)
How many times/week
Up to 2 times	233	30.7	1.00
3 times or more	379	49.9	0.94 (0.84–1.06)
How many hours/day
Up to 2 h	274	36.1	1.00
3 h or more	338	44.5	1.02 (0.91–1.14)
Use of a cell phone
No	22	2.9	1.00
Yes	738	97.1	0.89 (0.66–1.19)
What posture is the cell phone used
Standing	285	37.5	1.16 (1.04–1.29)a
Sitting	411	54.1	1.10 (0.99–1.23)
Lying down	458	60.3	1.16 (1.04–1.30)a
Semi-lying	301	39.6	1.27 (1.14–1.40)a
Daily use time
Up to 2 h	136	17.9	1.00
3 h or more	602	79.2	1.23 (1.06–1.42)a
Use of tablet
No	576	75.8	1.00
Yes	184	24.2	1.29 (1.15–1.44)a
What posture is the tablet used
Standing	44	5.8	1.12 (0.90–1.38)
Sitting	107	14.1	1.04 (0.86–1.27)
Lying down	85	11.2	0.99 (0.82–1.20)
Semi-lying	52	6.8	1.16 (0.95–1.41)
Daily use time
Up to 2 h	136	17.9	1.00
3 h or more	48	6.3	1.07 (0.87–1.32)

CI, confidence interval; PR, prevalence ratio.

^aFactor associated.