Table 5.
The OR of MS according to time period of birth in a large registry-based sibling study in Norway.
| Born in or before 1958 |
Born after 1958 |
|||
|---|---|---|---|---|
| No. of cases/controls | OR (95% CI)a | No. of cases/controls | OR (95% CI)a | |
| Level of education | ||||
| Primary | 459/976 | Ref. | 544/1128 | Ref. |
| Secondary | 1082/2140 | 1.00 (0.84–1.20) | 1104/2291 | 1.00 (0.85–1.17) |
| Undergraduate | 386/825 | 0.81 (0.64–1.04) | 664/1238 | 0.87 (0.72–1.07) |
| Graduate | 89/240 | 0.72 (0.50–1.03) | 166/355 | 0.84 (0.63–1.12) |
| p trend | 0.04 | 0.11 | ||
MS: multiple sclerosis; OR: odds ratio; CI: confidence interval.
a
Effect estimates calculated using conditional logistic regression comparing level of education in patients with the level of their own siblings. All estimates are adjusted for age, sex, parental education and number of siblings.