Table 3.
Effects of mobile phone use at baseline (weekly minutes of conversation) on different indicators of sleep quality at follow-up stratified by country and gender.
| Sweden | Finland | Men | Women | |
|---|---|---|---|---|
| Sleep outcome | β (95% CI)1 | β (95% CI)1 | β (95% CI)1 | β (95% CI)1 |
| Sleep disturbance | ||||
| <72 min | 0.0 (Ref) | 0.0 (Ref) | 0.0 (Ref) | 0.0 (Ref) |
| 72–163 min | −0.44 (−1.00, 0.12) | 0.58 (−0.64, 1.80) | −0.33 (−1.04, 0.37) | −0.19 (−0.92, 0.54) |
| 164–257 min | −1.07 (−1.74, −0.39) | −0.54 (−2.10, 1.02) | −1.61 (−2.44, −0.78) | −0.39 (−1.29, 0.51) |
| ≥258 min | −0.34 (−1.13, 0.45) | −1.78 (−3.61, 0.04) | −0.40 (−1.35, 0.54) | −0.62 (−1.71, 0.47) |
| Sleep adequacy | ||||
| <72 min | 0.0 (Ref) | 0.0 (Ref) | 0.0 (Ref) | 0.0 (Ref) |
| 72–163 min | −1.10 (−1.88, −0.33) | 0.50 (−1.27, 2.26) | −0.47 (−1.51, 0.56) | −1.12 (−2.09, −0.15) |
| 164–257 min | 0.01 (−0.91, −0.94) | −0.14 (−2.40, 2.12) | 0.99 (−0.23, 2.21) | −0.87 (−2.06, 0.33) |
| ≥258 min | −1.07 (−2.16, 0.02) | 0.40 (−2.24, 3.03) | −0.56 (−1.96, 0.83) | −0.99 (−2.44, 0.47) |
| Daytime somnolence | ||||
| <72 min | 0.0 (Ref) | 0.0 (Ref) | 0.0 (Ref) | 0.0 (Ref) |
| 72–163 min | 0.30 (−0.20, 0.79) | −0.64 (−1.78, 0.49) | 0.19 (−0.46, 0.84) | 0.04 (−0.59, 0.67) |
| 164–257 min | 0.35 (−0.24, 0.94) | −0.20 (−1.65, 1.25) | −0.51 (−1.27, 0.25) | 0.87 (0.09, 1.65) |
| ≥258 min | 0.32 (−0.37, 1.02) | −0.00 (−1.70, 1.69) | 0.18 (−0.69, 1.05) | 0.27 (−0.67, 1.21) |
| OR (95% CI)1 | OR (95% CI)1 | OR (95% CI)1 | OR (95% CI)1 | |
| Insomnia2 | n = 1137 | n = 139 | n = 462 | n = 814 |
| <72 min | 1.0 (Ref) | 1.0 (Ref) | 1.0 (ref) | 1.0 (ref) |
| 72–163 min | 1.10 (0.94–1.28) | 0.96 (0.63–1.47) | 0.94 (0.73–1.20) | 1.16 (0.97–1.40) |
| 164–257 min | 1.10 (0.91–1.32) | 0.93 (0.54–1.60) | 0.92 (0.69–1.23) | 1.16 (0.93–1.46) |
| ≥258 min | 1.35 (1.11–1.66) | 0.60 (0.30–1.21) | 1.25 (0.93–1.68) | 1.21 (0.94–1.57) |
| Sleep latency > 30 min2 | n = 1406 | n = 207 | n = 559 | n = 1054 |
| <72 min | 1.0 (Ref) | 1.0 (Ref) | 1.0 (ref) | 1.0 (ref) |
| 72–163 min | 0.88 (0.76–1.01) | 1.04 (0.73–1.49) | 0.78 (0.63–0.97) | 1.00 (0.85–1.18) |
| 164–257 min | 0.74 (0.62–0.89) | 0.89 (0.56–1.42) | 0.60 (0.45–0.80) | 0.90 (0.73–1.11) |
| ≥258 min | 1.03 (0.85–1.25) | 1.70 (1.07–2.70) | 1.04 (0.80–1.36) | 1.18 (0.93–1.48) |
1
Adjusted for age, gender (in country specific analyses), country (in gender specific analyses), 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.
2
Restricted to individuals who did not report the outcome at baseline. In Sweden 1976 participants reported insomnia, and 3412 reported sleep latency >30 min at baseline. Corresponding numbers for Finland was 224 and 556, respectively.