Table 4

Associations of computer and cell phone use with BMI at 17 y



Mean BMI (SD)
Linear regression, adjusted for gender, physical exercise, and parents' education







Beta coefficient, 95% confidence interval
p-value

Computer at home
No
21.3 (2.9)
-
-

Yes




     without Internet
21.6 (3.0)
0.57 (0.15 to 0.98)
0.007

     with Internet
21.3 (3.1)
0.23 (-0.09 to 0.56)
0.16
Weekly computer use for school, work, and recreation (hours)
0–1
21.1 (3.0)
-
-

>1–3
21.2 (2.9)
0.10 (-0.21 to 0.41)
0.52

>3–6
21.3 (2.9)
0.12 (-0.20 to 0.44)
0.46

>6–12
21.6 (3.0)
0.31 (-0.0.38 to 0.65)
0.081

>12–115
21.7 (3.4)
0.25 (-0.14 to 0.65)
0.21
Cell phone bill
(continuous)
-
0.18 (0.06 to 0.30)
0.003
Cell phone bill in a month (euros)
No cell phone
21.0 (3.4)
-0.53 (-1.09 to 0.04)
0.068

< 10
21.3 (3.6)
-0.20 (-0.60 to 0.21)
0.34

10 – 20
21.3 (2.9)
-0.25 (-0.49 to -0.006)
0.045

20 – 35
21.4 (2.9)
-
-

35 – 85
21.7 (2.9)
0.29 (-0.04 to 0.63)
0.085

Lajunen et al. BMC Public Health 2007 7:24   doi:10.1186/1471-2458-7-24