Table 1 Comparison of characteristics and % of missing data across time points

From: Association of BMI category with change in children’s physical activity between ages 6 and 11 years: a longitudinal study

  Age 6 Age 9 Age 11
  N % or mean (sd) N % or mean (sd) N % or mean (sd)
N 1299   1223   1296  
BMI z-score 1271 0.27 (0.95) 1217 0.35 (1.07) 1285 0.35 (1.16)
 % Normal weight   81%   75%   71%
 % Overweight   11%   11%   14%
 % Obese   8%   13%   15%
% female 1299 49% 1223 55% 1296 52%
Highest household education 1176   1125   1191  
 Up to GCSE or equiv   20%   19%   20%
 A level or equiv   28%   29%   26%
 University degree or equiv   36%   36%   37%
 Higher degree   16%   17%   17%
Average weekday activity       
 MVPA (min) 1087 68.0 (21.1) 1059 62.9 (22.0) 1129 60.6 (23.1)
 Light (min) 1087 244.2 (39.9) 1059 223.6 (41.7) 1129 210.1 (42.7)
 Sedentary time (min) 1087 372.0 (59.3) 1059 445.7 (64.5) 1129 480.4 (69.8)
 Wear time (min) 1087 684.2 (68.4) 1059 732.2 (68.5) 1129 751.1 (76.6)
 % of time in MVPA 1087 10% 1059 9% 1129 8%
 % of time in sedentary 1087 54% 1059 61% 1129 64%
Average weekend activity       
 MVPA (min) 980 66.3 (27.6) 942 61.5 (31.8) 976 53.4 (31.3)
 Light (min) 980 234.0 (46.6) 942 215.1 (50.2) 976 195.2 (49.8)
 Sedentary time (min) 980 339.1 (76.0) 942 401.9 (83.7) 976 441.8 (88.8)
 Wear time (min) 980 639.5 (85.2) 942 678.5 (90.3) 976 690.4 (95.9)
 % of time in MVPA 980 10% 942 9% 976 8%
 % of time in sedentary 980 53% 942 59% 976 64%
 % MVPA > 60 min 1023 63% 1026 46% 1062 41%