Table 3

Outdoor time and near work time before and during the COVID-19 pandemic in the COVID-19 cohort

Before COVID-19During COVID-19DifferencesP value
Mean (SD)Mean (SD)Mean (SD)
Outdoor time (hours/day)1.27 (1.12)0.41 (0.90)−0.86 (1.20)<0.001*
 Outdoor for sports0.64 (0.70)0.13 (0.32)−0.51 (0.69)<0.001*
 Outdoor for leisure0.63 (0.72)0.28 (0.81)−0.35 (0.84)<0.001*
Diopter*hour10.18 (6.78)19.51 (10.23)9.24 (7.72)<0.001*
Total near work time(hours/day)3.42 (2.50)8.05 (4.49)4.58 (3.62)<0.001*
 Reading and writing time2.03 (1.32)2.18 (1.52)0.15 (1.26)<0.006*
  Doing paper homework1.03 (0.70)0.81 (0.71)−0.23 (0.77)<0.001*
  Reading0.44 (0.51)0.69 (0.73)0.25 (0.58)<0.001*
  Drawing and writing0.55 (0.66)0.69 (0.78)0.14 (0.64)<0.001*
 Screen time hours/day)2.45 (2.32)6.89 (4.42)4.47 (3.60)<0.001*
  Watching TV1.04 (0.89)2.07 (1.65)1.03 (1.34)<0.001*
  Using computer0.29 (0.50)1.26 (1.22)0.97 (1.18)<0.001*
  Electronic game/ using smartphone or tablet PC for leisure0.87 (1.38)2.28 (2.52)1.41 (1.93)<0.001*
  Using smartphone or tablet PC for learning0.27 (0.49)1.29 (1.15)1.01 (1.16)<0.001*
  • Pairwise t tests were used to test the differences of outdoor time and near work time before and during the COVID-19 pandemic

  • *Significant level was set at 0.05; Diopter* hours were defined as: (study hours+leisure reading hours)×3 + (video game or home computer work hours)×2 + (television hours)×1.