Table 4. Logistic regression analysis of the relationship between decrease in tear secretion in VDT users and working duration.
Category | Sub category | Decrease in tear secretion (Schirmer score ≤5 mm) | OR† * | 95% C I§ | |
Cases | Controls | ||||
(n = 57) | (n = 544) | ||||
VDT working year | <4 | 8 | 170 | reference | |
4–8 | 11 | 119 | 1.84 | 0.69, 5.04 | |
8–12 | 18 | 148 | 2.49 | 1.02, 6.55 | |
≥12 | 20 | 107 | 3.61 | 1.39, 10.26 | |
P trend = 0.012 | |||||
Daily VDT hour | ≤2 | 6 | 96 | reference | |
2–4 | 13 | 145 | 1.47 | 0.55, 4.39 | |
4–6 | 10 | 129 | 1.35 | 0.47, 4.23 | |
6–8 | 16 | 125 | 2.30 | 0.87, 6.89 | |
>8 | 12 | 49 | 4.27 | 1.47, 13.66 | |
P trend = 0.005 |
†OR: odds ratio;
*Adjusted for gender and age;
§Confidence interval.