Table 7.
Relative and absolute reliability of steps, walking, and sedentary time assessed with ActivPAL3™, SENS motion®, and direct observations in older medical patients (N = 12).
| Comparison | Mean (SD) of both assessments (sec) | Mean (SD) difference (sec) | p value for difference | ICC2.1 (95% CI) | SEM (SEM%) | MDC95 (MDC%) |
|---|---|---|---|---|---|---|
| Steps | ||||||
| ActivPAL vs. observed | 229.1 (45.8) | -43.6 (29.6) | <0.001 | 0.582 (-0.103-0.882) | 29.6 (13) | 82.0 (36) |
| SENS vs. observed | 235.2 (41.1) | -31.5 (23.0) | 0.001 | 0.678 (-0.076-0.916) | 23.3 (10) | 64.6 (27) |
| ActivPAL vs. SENS | 213.4 (47.9) | -12.1 (24.8) | 0.1 | 0.858 (0.579-0.957) | 18.1 (8) | 59.2 (24) |
| Walking time | ||||||
| ActivPAL vs. observed | 160.0 (26.4) | -25.8 (16.3) | <0.001 | 0.582 (-0.102-0.884) | 17.1 (11) | 47.4 (30) |
| SENS vs. observed | 165.8 (25.1) | -14.2 (9.0) | <0.001 | 0.816 (-0.038-0.960) | 10.8 (7) | 29.9 (18) |
| ActivPAL vs. SENS | 152.9 (25.5) | -11.5 (12.7) | 0.009 | 0.813 (0.243-0.950) | 11.0 (7) | 30.5 (20) |
| Sedentary time | ||||||
| ActivPAL vs. observed | 184.8 (9.8) | -9.3 (10.7) | 0.012 | 0.416 (-0.092-0.778) | 7.5 (4) | 20.8 (11) |
| SENS vs. observed | 183.4 (9.2) | -12.0 (11.9) | 0.005 | 0.264 (-0.141-0.671) | 7.9 (4) | 21.9 (12) |
| ActivPAL vs. SENS | 178.8 (12.3) | 2.8 (13.6) | 0.5 | 0.544 (-0.015-0.844) | 8.3 (5) | 23.0 (13) |
ICC: intraclass correlation coefficient; SEM: standard error of measurement (SD of mean [both assessments] × √1 − ICC); MDC: minimal detectable change (SEM × √2 × 1.96, SEM% = 100 × SEM/mean). SEM and MDC indicate measurement error (in sec) at group and individual levels, respectively. ActivPAL: ActivPAL3™ monitor; SENS: SENS motion®.