Table 2.
Odds ratio (OR) to develop impaired sleep quality between BL and FUP in relation to nocturnal awakenings due to incoming mobile phone calls or text message. Significant associations are displayed in bold.
| Sleep Quality Indicator | New Onset of Sleep Problem (Total N) | Crude | Model I 2 | Model II 3 |
|---|---|---|---|---|
| OR (95% CI) | OR (95% CI) | OR (95% CI) | ||
| Exposure status BL/exposure status FUP 4 | ||||
| Problems falling asleep (N1 = 461) | ||||
| Exposed/non exposed 4 | 12 (65) | 0.74 (0.38–1.45) | 0.64 (0.31–1.33) | 0.64 (0.31–1.33) |
| Non exposed/non exposed | 84 (357) | 1 (reference) | 1 (reference) | 1 (reference) |
| Exposed/exposed | 7 (15) | 2.87 (1.01–8.14) | 3.51 (1.05–11.74) | 3.44 (1.03–11.54) |
| Non exposed/exposed | 9 (24) | 1.97 (0.83–4.66) | 2.16 (0.83–5.64) | 2.31 (0.87–6.09) |
| Restless sleep (N = 652) | ||||
| Exposed/non exposed 4 | 14 (84) | 1.41 (0.75–2.66) | 1.29 (0.65–2.55) | 1.32 (0.67–2.62) |
| Non exposed/non exposed | 66 (499) | 1 (reference) | 1 (reference) | 1 (reference) |
| Exposed/exposed | 11 (29) | 4.32 (1.95–9.58) | 5.66 (2.24–14.26) | 5.39 (2.13–13.65) |
| Non exposed/exposed | 9 (40) | 2.05 (0.93–4.52) | 2.07 (0.85–5.08) | 2.02 (0.82–4.93) |
| Involuntary nocturnal awakenings (N = 686) | ||||
| Exposed/non exposed 4 | 12 (89) | 1.44 (0.73–2.82) | 1.09 (0.53–2.25) | 1.07 (0.52–2.22) |
| Non exposed/non exposed | 53 (528) | 1 (reference) | 1 (reference) | 1 (reference) |
| Exposed/exposed | 4 (28) | 1.54 (0.51–4.60) | 1.80 (0.54–5.97) | 1.82 (0.54–6.11) |
| Non exposed/exposed | 6 (41) | 1.58 (0.63–3.94) | 1.47 (0.54–4.04) | 1.62 (0.58–4.54) |
| Too early morning awakenings (N = 651) | ||||
| Exposed/non exposed 4 | 17 (95) | 1.09 (0.62–1.96) | 0.79 (0.43–1.48) | 0.79 (0.42–1.47) |
| Non exposed/non exposed | 80 (485) | 1 (reference) | 1 (reference) | 1 (reference) |
| Exposed/exposed | 9 (32) | 1.97 (0.88–4.42) | 1.85 (0.77–4.42) | 1.82 (0.76–4.39) |
| Non exposed/exposed | 6 (39) | 0.92 (0.37–2.26) | 0.97 (0.37–2.56) | 1.00 (0.37–2.65) |
| General sleep quality 5 (N = 639) | ||||
| Exposed/non exposed 4 | 12 (83) | 1.73 (0.87–3.43) | 1.81 (0.87–3.78) | 1.83 (0.88–3.83) |
| Non exposed/non exposed | 43 (487) | 1 (reference) | 1 (reference) | 1 (reference) |
| Exposed/exposed | 5 (33) | 1.82 (0.67–4.96) | 2.47 (0.82–7.45) | 2.39 (0.79–7.22) |
| Non exposed/exposed | 9 (36) | 3.40 (1.50–7.70) | 3.64 (1.48–8.95) | 3.69 (1.49–9.12) |
1 Number of observations relate to the symptom-free participants at BL for each symptom. 2 Model I adjusted for age, sex, class level at BL, nationality, school level, physical activity at FUP, smoking status at FUP, alcohol consumption at FUP, area of residence, education of parents, number of days between BL and FUP and body height difference between BL and FUP. 3 Model II additionally adjusted for daytime mobile phone use: Number of mobile phone calls and the number of text messages per day, the duration actively spent on the Internet with the mobile phone. 4 Exposure status relates to nocturnal awakenings due to incoming mobile phone calls or text messages. Exposed = Nocturnal awakenings due to mobile phone at least once per month. 5 Combined sleep quality measure of the four preceding sleep quality indicators. Sleeping problems prevalent / not prevalent as defined by the guidelines of the Swiss Health Survey. CI: Confidence Interval. OR: Odds Ratio.