Table 4

Risk of ACIS associated with OC use among women born in 1945 or later

Cases (n = 133)Controls (n = 478)OR1 (95% CI)aOR2 (95% CI)a
n%n%
OC use
 Never86.17416.21.0
 Ever12493.938483.82.7 (1.2–5.8)
Duration of use (mo)
 0–<186.17416.21.0
 1–716448.525054.62.1 (1.0–4.8)
 72–1434030.310122.13.4 (1.5–8.0)
 144+2015.2337.25.5 (2.1–14.6)
P < 0.001b
Age at first use (yrs)
 Never86.17416.21.0
 20+4937.116836.72.6 (1.1–5.8)1.0
 18–193123.511024.02.4 (1.0–5.5)0.8 (0.5–1.4)
 16–173123.57917.22.9 (1.2–6.9)0.9 (0.5–1.7)
 <15139.8275.93.7 (1.3–10.4)1.1 (0.5–2.5)
p = 0.02b
Interval since last use (yrs)
 Never86.17416.21.0
 10+5138.619041.42.2 (0.9–5.0)1.0
 <103828.812427.12.4 (1.0–5.6)0.7 (0.4–1.3)
 Current3526.57015.34.5 (1.9–10.9)1.0 (0.5–2.1)
P < 0.001b
  • a OR1 is adjusted for age (continuous, linear), lifetime number of sex partners (1, 2–4, 5+), and interval since last screening Pap (<12 months, 12–35 months, 36+ months). OR2 is adjusted as described for OR1 but is also adjusted for duration of OC use, and the comparison is restricted to OC users.

  • b Test for trend.