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 years111211Reference
    ≥5 years29145.241.58 to 17.38
Length of employment 1971 to 1997
    <5 years97241Reference
    ≥5 years43110.820.34 to 1.97
Reproductive factors
    Nulliparous1120.770.14 to 4.10
    Age at first birth ⩽24 y43161.920.76 to 4.84
    Age at first birth 25–29 y62141Reference
    Age at first birth 30–34 y1520.460.09 to 2.39
    Age at first birth ≥35 y910.440.05 to 3.96