Recalled phone use compared to actual phone use: duration of calls
| Country | Subjects (n) | Mean duration (min)/month | Correlation coefficient | Weighted kappa (95% CI)* | Ratio of recalled to actual call duration | ||
|---|---|---|---|---|---|---|---|
| Geometric mean ratio (95% CI) | 95% limits of agreement† | % subjects with ratio 0.5–2 | |||||
| *Weighted kappa statistic for quintiles of the distribution of actual number of calls. | |||||||
| †95% limits of agreement: mean plus/minus two standard deviations.15,16 | |||||||
| ‡Sweden and the UK are the excluded countries. | |||||||
| Australia | 44 | 305 | 0.81 | 0.54 (0.34–0.75) | 1.39 (1.04–1.85) | 0.20–9.65 | 45% |
| Denmark | 44 | 255 | 0.55 | 0.40 (0.21–0.59) | 1.34 (1.01–1.78) | 0.19–9.25 | 48% |
| Finland | 76 | 910 | 0.56 | 0.35 (0.20–0.51) | 1.53 (1.19–1.79) | 0.16–14.30 | 43% |
| France | 64 | 656 | 0.50 | 0.40 (0.24–0.56) | 1.45 (1.09–1.92) | 0.14–14.45 | 45% |
| Germany | 75 | 187 | 0.52 | 0.27 (0.12–0.42) | 1.03 (0.74–1.44) | 0.05–19.89 | 33% |
| Israel | 38 | 2015 | 0.57 | 0.28 (0.04–0.52) | 1.43 (0.93–2.19) | 0.10–21.24 | 39% |
| Italy | 89 | 1071 | 0.65 | 0.39 (0.26–0.51) | 2.18 (1.71–2.77) | 0.21–22.47 | 40% |
| New Zealand | 20 | 104 | 0.77 | 0.56 (0.26–0.86) | 0.70 (0.48–1.04) | 0.12–4.10 | 40% |
| Norway | 45 | 193 | 0.54 | 0.33 (0.15–0.50) | 0.56 (0.40–0.78) | 0.06–5.67 | 40% |
| Sweden | 43 | 514 | 0.70 | 0.37 (0.17–0.56) | 1.46 (1.03–2.08) | 0.14–15.35 | 35% |
| UK-North SMP study | 39 | 285 | 0.80 | 0.63 (0.41–0.85) | 1.06 (0.78–1.43) | 0.16–7.12 | 69% |
| UK-North operator study | 86 | 206 | 0.58 | 0.35 (0.22–0.48) | 2.47 (1.84–3.31) | 0.15–39.45 | 36% |
| Total all countries | 663 | 0.69 | 0.49 (0.44–0.55) | 1.42 (1.29–1.56) | 0.12–17.37 | 42% | |
| Excluding countries not using CAPI‡ | 495 | 0.70 | 0.48 (0.41–0.54) | 1.31 (1.18–1.46) | 0.11–15.47 | 41% | |
| Excluding UK-North operator study | 557 | 0.70 | 0.48 (0.42–0.54) | 1.31 (1.18–1.44) | 0.12–14.73 | 43% | |