Table 3.
Estimated Effect of Sunlight and Ultraviolet Light Exposure (UV Index) on Time to Recurrence of Ocular Herpes Simplex Virus Among 308 Participants in the Herpetic Eye Disease Study, 1993–1997
| Model and Sun Exposure, hours/week | No. of Events | Person- Weeks of Follow-up | Hazard Ratio | 95% Confidence Intervala |
|---|---|---|---|---|
| Crude Model | ||||
| Total | ||||
| ≤7 | 27 | 7,169 | 1 | |
| ≥8 | 17 | 2,994 | 1.46 | 0.79, 2.68 |
| UV index <4 | ||||
| ≤7 | 18 | 3,619 | 1 | |
| ≥8 | 4 | 949 | 0.81 | 0.27, 2.41 |
| UV index ≥4 | ||||
| ≤7 | 9 | 3,550 | 1 | |
| ≥8 | 13 | 2,045 | 2.42 | 1.00, 5.84 |
| Weighted Modelb | ||||
| Total | ||||
| ≤7 | 27 | 7,169 | 1 | |
| ≥8 | 17 | 2,994 | 1.85 | 0.89, 3.88 |
| UV index <4 | ||||
| ≤7 | 18 | 3,619 | 1 | |
| ≥8 | 4 | 949 | 0.84 | 0.27, 2.63 |
| UV index ≥4 | ||||
| ≤7 | 9 | 3,550 | 1 | |
| ≥8 | 13 | 2,045 | 3.10 | 1.14, 8.48 |
Abbreviation: UV, ultraviolet.
a 95% confidence intervals for results stratified by UV index were calculated using robust methods to account for variance between imputations.
b The weighted model accounted for time-varying psychological stress and use of contact lenses and for baseline age and gender.