Table 3.
Effect of Year of Birth on Age at Menarche Among Female Israeli Army Recruits, 1986–2000, According to Geographic Origin, Smoking Status, and Father’s Education
| N | Regression coefficient | 95% Confidence Interval | P | |
|---|---|---|---|---|
| Simple model | 11,392 | −0.034 | −0.042 to −0.029 | <.001 |
| Origin | ||||
| West | 4930 | −0.035 | −0.045 to −0.025 | <.001 |
| East | 6428 | −0.035 | −0.044 to −0.027 | <.001 |
| Smoking | ||||
| Current smokers | 2463 | −0.036 | −0.050 to −0.022 | <.001 |
| Past smokers | 253 | −0.070 | −0.115 to −0.026 | .002 |
| Never smoked | 8587 | −0.035 | −0.042 to −0.027 | <.001 |
| Father’s years of education | ||||
| <12 | 3292 | −0.038 | −0.051 to −0.026 | <.001 |
| 12 | 4264 | −0.034 | −0.045 to −0.023 | <.001 |
| >12 | 2995 | −0.035 | −0.047 to −0.023 | <.001 |