Table 1
Adjusted matched odds ratios from conditional logistic regression of breast cancer risk among cases and controls of cabin attendants according to length of employment and reproductive factors
| Controls (n=140) | Cases (n=35) | Matched odds ratio* | 95% CI | |
|---|---|---|---|---|
| *Odds ratios have been calculated in a unique multivariate analysis, taking into account simultaneously all the variables. | ||||
| Length of employment 1947 to 1970 | ||||
| <5 years | 111 | 21 | 1 | Reference |
| ≥5 years | 29 | 14 | 5.24 | 1.58 to 17.38 |
| Length of employment 1971 to 1997 | ||||
| <5 years | 97 | 24 | 1 | Reference |
| ≥5 years | 43 | 11 | 0.82 | 0.34 to 1.97 |
| Reproductive factors | ||||
| Nulliparous | 11 | 2 | 0.77 | 0.14 to 4.10 |
| Age at first birth ⩽24 y | 43 | 16 | 1.92 | 0.76 to 4.84 |
| Age at first birth 25–29 y | 62 | 14 | 1 | Reference |
| Age at first birth 30–34 y | 15 | 2 | 0.46 | 0.09 to 2.39 |
| Age at first birth ≥35 y | 9 | 1 | 0.44 | 0.05 to 3.96 |
