Table 2.
Comparison of Sleep Parameters Calculated by PSG and Actigraphy (N = 68 pairs)
| Mean ± SD | Difference PSG-Actigraphy mean ± SD | Absolute Difference mean ± SD | paired t-test P-value* | ICC (95% CI) | |
|---|---|---|---|---|---|
| TST, min | |||||
| PSG: | 342.8 ± 70.2 | ||||
| Actigraphy Mode: | |||||
| PIM | 360.7 ± 81.1 | −17.9 ± 50.1 | 44.2 ± 29.1 | 0.0045 | 0.76(0.64, 0.84) |
| TAT | 375.8 ± 85.6 | −33.0 ± 57.6 | 55.7 ± 35.7 | <0.0001 | 0.66(0.50, 0.77) |
| ZCM | 317.2 ± 107.6 | 25.6 ± 86.0 | 61.2 ± 65.3 | 0.0167 | 0.53(0.33, 0.68) |
| WASO, min | |||||
| PSG: | 83.7 ± 53.3 | ||||
| Actigraphy Mode: | |||||
| PIM | 76.9 ± 55.5 | 6.7 ± 49.9 | 38.8 ± 31.7 | 0.2657 | 0.58(0.40, 0.72) |
| TAT | 62.9 ± 55.6 | 20.7 ± 57.1 | 48.6 ± 36.0 | 0.0036 | 0.41(0.19, 0.57) |
| ZCM | 98.7 ± 74.1 | −15.1 ± 82.0 | 55.1 ± 62.2 | 0.1353 | 0.19(−0.05,0.41) |
| SE, % | |||||
| PSG: | 75.4 ± 12.1 | ||||
| Actigraphy Mode: | |||||
| PIM | 79.2 ± 14.2 | −3.9 ± 11.1 | 9.8 ± 6.5 | 0.0056 | 0.61(0.44, 0.74) |
| TAT | 82.4 ± 14.6 | −7.0 ± 13.0 | 12.4 ± 7.9 | <0.0001 | 0.44(0.23, 0.61) |
| ZCM | 69.5 ± 22.1 | 5.9 ± 20.1 | 13.9 ± 15.6 | 0.0192 | 0.33(0.11, 0.53) |
*
P-value is from a t-test on the paired data for difference. P-values for paired t-test on absolute difference was also significant.
TST = total sleep time, WASO = wake after sleep onset, SE = sleep efficiency, PSG = polysomnography, PIM = proportional integration mode, TAT = time above threshold, ZCM = zero crossings mode, SD = standard deviation, CI = confidence interval, ICC = intraclass correlation coefficient