Table 4.
Effects of mobile phone use at baseline (weekly minutes of conversation) in GSM and UMTS systems (first base station) on different sleep outcomes at follow-up.
| Sleep disturbance | Sleep adequacy | Daytime somnolence | Insomnia1 | Sleep latency > 30 min1 | |
|---|---|---|---|---|---|
| Exposure indicator2 | β (95% CI)3 | β (95% CI)3 | β (95% CI)3 | OR (95% CI)3 | OR (95% CI)3 |
| All calls, UMTS call time divided by 150 | |||||
| <24 min | 0.0 (Ref) | 0.0 (Ref) | 0.0 (Ref) | 1.0 (Ref) | 1.0 (Ref) |
| 24–84 min | −0.63 (−1.15, −0.10) | −0.19 (−0.91, 0.54) | 0.12 (−0.34, 0.58) | 1.17 (1.01–1.36) | 0.91 (0.79–1.04) |
| 85–189 min | −0.58 (−1.20, 0.04) | −0.33 (−1.19, 0.54) | 0.33 (−0.22, 0.88) | 1.18 (0.99–1.40) | 0.91 (0.78–1.07) |
| 190 + min | −1.22 (−1.95, −0.48) | −0.18 (−1.20, 0.83) | −0.06 (−0.71, 0.59) | 1.09 (0.89–1.33) | 0.88 (0.73–1.07) |
| Time on GSM network4 | |||||
| <24 min | 0.0 (Ref) | 0.0 (Ref) | 0.0 (Ref) | 1.0 (Ref) | 1.0 (Ref) |
| 24–84 min | −0.64 (−1.17, −0.11) | −0.16 (−0.90, 0.57) | 0.12 (−0.35, 0.59) | 1.17 (1.01–1.36) | 0.91 (0.80–1.04) |
| 85–189 min | −0.55 (−1.18, 0.07) | −0.44 (−1.30, 0.42) | 0.34 (−0.21, 0.89) | 1.20 (1.00–1.42) | 0.93 (0.79–1.08) |
| 190 + min | −1.24 (−1.99, −0.50) | −0.35 (−1.39, 0.68) | −0.03 (−0.69, 0.64) | 1.14 (0.93–1.40) | 0.89 (0.74–1.08) |
| Time on UMTS network4 | |||||
| 0 min | 0.0 (Ref) | 0.0 (Ref) | 0.0 (Ref) | 1.0 (Ref) | 1.0 (Ref) |
| 1–34 min | −0.07 (−0.60, 0.46) | −0.37 (−1.10, 0.36) | −0.21 (−0.67, 0.26) | 1.06 (0.91–1.23) | 1.12 (0.98–1.29) |
| 35–121 min | 0.02 (−0.62, 0.66) | −0.85 (−1.74, 0.03) | 0.19 (−0.37, 0.76) | 1.19 (1.00–1.42) | 0.96 (0.81–1.13) |
| 122 + min | 0.21 (−0.54, 0.95) | −0.87 (−1.90, 0.17) | 0.45 (−0.22, 1.11) | 1.21 (0.98–1.48) | 1.19 (0.99–1.44) |
| Restricted to participants with only GSM call time5 | |||||
| <24 min | 0.0 (Ref) | 0.0 (Ref) | 0.0 (Ref) | 1.0 (Ref) | 1.0 (Ref) |
| 24–84 min | −0.71 (−1.54, 0.11) | 0.12 (−1.03, 1.27) | 0.06 (−0.67, 0.80) | 1.20 (0.94–1.54) | 0.95 (0.76–1.18) |
| 85–189 min | −0.54 (−1.42, 0.35) | −0.24 (−1.47, 1.00) | 0.25 (−0.54, 1.04) | 1.12 (0.86–1.46) | 0.99 (0.78–1.25) |
| 190 + min | −1.94 (−2.88, −1.00) | 0.00 (−1.30, 1.31) | −0.11 (−0.95, 0.73) | 1.08 (0.82–1.42) | 0.84 (0.65–1.08) |
1
Restricted to individuals who did not report the outcome at baseline
2
Categorized according to the 50th, 75th, and 90th percentiles.
3
All analyses were adjusted for age, gender, country, sleep outcome at baseline, current smoking, alcohol consumption, body mass index, educational level, weekly headache, mental and physical health score (SF-12), and diagnosis of depression.
4
GSM and UMTS calls were included in the same regression model.
5
n = 11,676.