Table 1.
Accelerometry-derived sedentary time estimates using 150 counts per minute (CPM) and convergent validity of the Global Physical Activity Questionnaire (GPAQ) and the Adult Sedentary Behaviour Questionnaire (ASBQ).
| Accelerometry Estimates | All (n = 78) | Self (n = 37) | Interview (n = 41) |
|---|---|---|---|
| Valid wearing day/week (median (IQR)) | 6.6 (6.0–7.0) | 7.0 (6.0–7.0) | 6.0 (5.5–7.0) |
| Valid wear time, min/day (mean ± SD) | 910.6 ± 82.2 | 915.6 ± 84.6 | 906.1 ± 80.8 |
| Total sedentary time, min/day (mean ± SD) | 663.8 ± 70.4 | 658.6 ± 65.8 | 668.5 ± 74.8 |
| Relative sedentary time (%) (mean ± SD) a | 73.1 ± 6.3 | 72.1 ± 5.5 | 73.9 ± 6.8 |
| Spearman’s rho (95% CI) | |||
| GPAQ single-item | 0.28 (0.11–0.47) * | 0.46 (0.18–0.68) * | 0.12 (−0.11–0.33) |
| ASBQ sum of domain-specific | 0.10 (−0.12–0.32) | 0.31 (−0.02–0.58) | −0.07 (−0.37–0.24) |
| Occupational sitting | 0.18 (−0.05–0.38) | 0.32 (0.03–0.59) | 0.11 (−0.20–0.41) |
| Transportation | 0.11 (−0.12–0.32) | 0.12 (−0.22–0.42) | 0.10 (−0.22–0.39) |
| Eating | 0.07 (−0.16–0.29) | 0.34 b (0.70–0.58) * | −0.17 b (−0.45–0.15) |
| Television viewing | 0.05 (−0.18–0.26) | 0.08 (−0.25–0.40) | 0.02 (−0.29–0.32) |
| Leisure-time computer use | −0.10 (−0.32–0.12) | 0.09 (−0.24–0.40) | −0.28 (−0.54–0.03) |
| Other leisure-time activities | −0.05 (−0.27–0.18) | 0.08 (−0.24–0.40) | −0.14 (−0.43–0.17) |
| MAE ± SD, min/day c | |||
| GPAQ single-item | 213.2 ± 150.9 | 207.5 ± 157.4 | 218.3 ± 146.5 |
| ASBQ sum of domain-specific | 164.1 ± 148.9 | 174.6 ± 167.8 | 154.7 ± 130.9 |
* Statistically significant at p < 0.05; a Total sedentary time divided by total wear time; b Average of all absolute errors between questionnaire and accelerometry-based sedentary time; c Significant difference in the correlation coefficients between self- and interviewer-administered groups, p < 0.05; Abbreviations: CI, confidence interval; CPM, counts per minute; IQR, interquartile range; MAE, Mean absolute error; SD, standard deviation.