Table 3

RRs and 95% CIs for the association between incidence of biopsy-confirmed proliferative and nonproliferative BBD and updated alcohol consumption (follow-up from 1991–1997)

Alcohol consumption (g/day)Person-yearsaNonproliferative BBDProliferative BBD
CasesRate/10,000 pybRRc95% CICasesRate/10,000 pybRRc95% CI
None163,156202121.0Reference404251.0Reference
<5151,566202131.080.89–1.32354230.970.84–1.11
5–14.958,37094161.331.04–1.71120210.810.66–0.99
≥1515,15818120.960.59–1.5637240.960.69–1.33
P = 0.16dP = 0.21d
  • a Person-years are the same for all case types in the table.

  • b Rate/10,000 py is the crude rate.

  • c RR adjusted for age and BMI (additional adjustment for age at menarche, smoking status, use of oral contraceptives, parity, age at first birth, and family history of breast cancer in logistic regression models did not alter the associations presented here).

  • d Test for linear trend across groups of alcohol intake.