Table 1.
Comparisons of change between study groups in self-reported anxiety, eye strain, sleep score, and time spent on different near-work activities between baseline and the 2-week follow-up (intention-to-treat analysis).
| Variable | Intervention group (n=485), mean (95% CI) | Control group (n=469), mean (95% CI) | Difference in change between groups, mean (95% CI) | P valuea | ||
| Anxiety scoreb,c |
|
|
||||
|
|
Baseline | 3.72 (3.69 to 3.76) | 3.67 (3.64 to 3.70) |
|
|
|
|
|
2-week follow-up | 3.49 (3.46 to 3.52) | 3.79 (3.76 to 3.83) |
|
|
|
|
|
Change (follow-up – baseline) | –0.23 (–0.27 to –0.20) | 0.12 (0.09 to 0.16) | –0.36 (–0.63 to –0.08) | .02d | |
| Eye strain scoreb,c |
|
|
||||
|
|
Baseline | 1.21 (1.19 to 1.23) | 1.08 (1.06 to 1.10) |
|
|
|
|
|
2-week follow-up | 1.13 (1.11 to 1.15) | 1.15 (1.12 to 1.18) |
|
|
|
|
|
Change (follow-up – baseline) | –0.08 (–0.10 to 0.06) | 0.07 (0.05 to 0.09) | –0.15 (–0.26 to –0.03) | .02d | |
| Sleep disturbance scoreb,c |
|
|
||||
|
|
Baseline | 2.51 (2.50 to 2.52) | 2.53 (2.53 to 2.54) |
|
|
|
|
|
2-week follow-up | 2.57 (2.56 to 2.58) | 2.55 (2.54 to 2.56) |
|
|
|
|
|
Change (follow-up – baseline) | 0.06 (0.05 to 0.07) | 0.01 (0.002 to 0.02) | 0.05 (–0.03 to 0.13) | .22 | |
| Average daily time spent in near work, hours | ||||||
|
|
Screen timeb | |||||
|
|
Baseline | 2.68 (2.67 to 2.69) | 2.69 (2.68 to 2.70) |
|
|
|
|
|
2-week follow-up | 2.61 (2.60 to 2.62) | 2.61 (2.60 to 2.63) |
|
|
|
|
|
Change (follow-up – baseline) | –0.07 (–0.08 to –0.05) | –0.08 (–0.09 to –0.06) | 0.01 (–0.10 to 0.12) | .84 | |
|
|
Reading timeb |
|
|
|||
|
|
Baseline | 1.37 (1.35 to 1.38) | 1.29 (1.28 to 1.30) |
|
|
|
|
|
2-week follow-up | 1.34 (1.32 to 1.35) | 1.21 (1.20 to 1.22) |
|
|
|
|
|
Change (follow-up – baseline) | –0.03 (–0.05 to –0.01) | –0.08 (–0.09 to –0.06) | 0.05 (–0.09 to 0.18) | .47 | |
aLinear regression models adjusting for cluster effects within schools.
bSquare root transformed.
cHigher score indicates greater severity.
dSignificant.