Darcy Ummels

100 | Chapter 5 Results Participant Characteristics Twenty older adults were recruited for this study. The participant characteristics are displayed in Table 5.2. Table 5.2 Participant characteristics. Characteristic Participants ( n =20) Gender, male, n (%) 10 (50%) Age, years, mean (95% CI) 74.5 (70.9–77.6) Body weight, kilograms, mean (95% CI) a 86.1 (73.7–98.5) Body length, centimetres, mean (95% CI) 172.5 (167.6–176.9) Average walk speed, mean (95% CI) 1.1 (1.0–1.2) a There was one (5%) missing value for body weight. Inter ‐ Observer Reliability of the Video Observations The inter ‐ observer reliability of the video observations calculated for step count was high (ICCagreement 0.98, P <0.001 95% CI 0.95–0.99). The inter ‐ observer reliability of dynamic, standing, and sedentary time were also high (ICCagreement 0.98, P <0.001, 95% CI 0.95–0.99), (ICCagreement 0.99, P <0.001 95% CI 0.98–0.99), (ICCagreement, 1.0, P <0.001, 95% CI 0.99–1.0) respectively. The limits of agreement for step count ( − 58 to 62 steps), dynamic ( − 49 to 41 s), standing ( − 49 to 40 s) and sedentary time ( − 26 to 28 s) showed no systematic differences. A third observer had to be included in two cases. Step count Descriptive statistics for each activity tracker are shown in Table 5.3. The mean step count during the activity protocol counted by the video observation was 615 (566–664) steps. The MOX MissActivity had a mean step count of 602 (537–667) steps, the activPAL had a mean step count of 385 (336–433) steps and the Fitbit had a mean step count of 731 (590–873) steps. The values of the percentage error and the absolute percentage error are presented in Figure 5.2. The Bland ‐ Altman plots (Figure 5.3) show a slight overestimation of the number of steps in the MOX MissActivity , an overestimation in the activPAL and underestimation in the Fitbit. If the limits of agreement for the activPAL and Fitbit Alta HR are corrected for their respective bias they are − 141 to 140 and − 183 to 183, respectively.