Table 8.
Relative and absolute reliability of steps, walking, and sedentary time assessed with ActivPAL3™, SENS motion®, and direct observations in older patients with hip fracture (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 | 124.6 (83.7) | -95.8 (48.8) | <0.001 | 0.530 (-0.089-0.868) | 57.4 (46) | 159.1 (128) |
| SENS vs. observed | 139.3 (83.4) | -66.3 (48.4) | 0.001 | 0.660 (-0.081-0.910) | 48.2 (35) | 133.6 (96) |
| ActivPAL vs. SENS | 91.4 (82.5) | -29.5 (44.4) | 0.042 | 0.825 (0.431-9.949) | 14.4 (16) | 39.9 (44) |
| Walking time | ||||||
| ActivPAL vs. observed | 140.3 (47.5) | -126.5 (78.5) | <0.001 | 0.062 (-0.097-0.375) | 46.0 (33) | 127.5 (91) |
| SENS vs. observed | 184.5 (54.8) | -38.1 (36.8) | 0.004 | 0.664 (-0.003-0.903) | 31.8 (17) | 88.1 (48) |
| ActivPAL vs. SENS | 121.3 (51.5) | -88.4 (63.2) | 0.001 | 0.223 (-0.121-0.632) | 45.4 (37) | 125.8 (103) |
| Sedentary time | ||||||
| ActivPAL vs. observed | 196.5 (12.1) | 1.1 (2.9) | 0.2 | 0.970 (0.903-0.991) | 2.1 (1) | 5.8 (3) |
| SENS vs. observed | 192.9 (11.3) | -6.0 (6.6) | 0.010 | 0.756 0.157-0.932() | 5.6 (3) | 15.5 (8) |
| ActivPAL vs. SENS | 193.5 (12.1) | 7.0 (6.7) | 0.004 | 0.716 (0.030-0.933) | 6.4 (3) | 17.7 (9) |
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®.