Skip to main content

Table 2 Mean (SD), correlations and Bland-Altman output for Fitbit Zip and ActiGraph in school segments

From: Validating Fitbit Zip for monitoring physical activity of children in school: a cross-sectional study

  Fitbit Zip ActiGraph GT3x r Bias LoA LuA
Steps
 Class time 231.5 (298.2) 206.2 (222.9) 0.85** 25.2 − 209.6 260.3
 Physical education lesson 2354.0 (1279.6) 2008.7 (1172.5)** 0.96** 345.3 − 163.8 854.4
 Recess 472.2 (337.2) 388.5 (268.2)** 0.96** 83.7 −127.3 294.7
MVPA (min)
 Class time 0.6 (2.5) 0.9 (1.7)** 0.24** −0.3 −4.0 3.3
 Physical education lesson 17.8 (14.1) 15.4 (9.1)* 0.72** 2.4 −14.7 19.4
 Recess 2.1 (4.3) 2.4 (2.4)** 0.56** −0.3 −6.4 5.8
Sedentary time (min)
 Class time 37.5 (5.8) 33.8 (6.5)** 0.57** 3.6 −6.5 13.8
 Physical education lesson 11.1 (9.8) 13.7 (9.0)** 0.85** −2.6 −10.4 5.2
 Recess 5.5 (4.1) 5.4 (3.9) 0.87** 0.1 −3.7 3.9
  1. Note: * P < 0.05, ** P < 0.001, LoA lower limits of agreement, LuA upper limits of agreement. Differences between two devices according to Wilcoxon Signed Rank test are presented in column “ActiGraph GT3x”