Table 2:
Odds ratios (ORs) and 95% confidence intervals (CIs) for duration of use (four studies) of DMPA use, oral contraceptive use, parity and ovarian cancer risk
| Cases (%) n=5,064 | Controls (%) n=6,831 | Odds ratio* | 95% Confidence interval | |
|---|---|---|---|---|
|
| ||||
| DMPA use | ||||
| Never use | 5,009 (98.9%) | 6,685 (97.9%) | 1.0 | |
| 3–9 months (1–3 shots) | 24 (0.5%) | 42 (0.6%) | 0.92 | 0.54–1.57 |
| 12–18 months (4–6 shots) | 13 (0.3%) | 41 (0.6%) | 0.56 | 0.29–1.07 |
| 21+ months (7+ shots) | 18 (0.4%) | 63 (0.9%) | 0.44 | 0.26–0.77 |
| p-trend<0.001 | ||||
| Oral contraceptive use | ||||
| Never use | 1,956 (38.6%) | 1,889 (27.7%) | 1.0 | |
| 1–11 months | 580 (11.5%) | 613 (9.0%) | 1.01 | 0.88–1.16 |
| 12– 59 months | 1,202 (23.7%) | 1,701 (24.9%) | 0.76 | 0.68–0.84 |
| 60–119 months | 724 (14.3%) | 1,249 (18.3%) | 0.59 | 0.52–0.67 |
| 120+ months | 602 (11.9%) | 1,379 (20.2%) | 0.42 | 0.37–0.48 |
| p-trend<0.001 | ||||
| Parity | ||||
| 0 | 1,158 (22.9%) | 1,129 (16.5%) | 1.0 | |
| 1 | 734 (14.5%) | 944 (13.8%) | 0.81 | 0.70–0.94 |
| 2 | 1,457 (28.8%) | 2,224 (32.6%) | 0.65 | 0.57–0.74 |
| 3+ | 1,715 (33.9%) | 2,534 (37.1%) | 0.60 | 0.52–0.68 |
| p-trend<0.001 | ||||
*
Single model fit with DMPA use, oral contraceptive use, and parity; conditioned on OCAC study site, race/ethnicity, and age; adjusted for education level and breastfeeding.