Background: Concern has been raised that the risk of venous thromboembolism (VTE) in users of the ORTHO EVRA patch is higher compared to users of oral contraceptives (OCs).
Study design: We identified idiopathic cases of VTE and controls, matched on age and index date, from among women in the United States PharMetrics/IMS and MarketScan databases who were current users of the patch or levonorgestrel-containing OCs with 30 mcg of ethinyl estradiol. We calculated odds ratios (ORs) and 95% confidence intervals (CIs).
Results: The ORs (95% CI) for VTE in users of the patch compared to levonorgestrel-containing OCs were 2.0 (0.9-4.1) and 1.3 (0.8-2.1) in the PharMetrics and MarketScan databases, respectively. ORs (95% CI) restricted to women aged 39 years or younger were 1.4 (0.6-3.0) and 1.2 (0.7-2.0), respectively.
Conclusion: These results provide evidence that the risk of idiopathic VTE in users of the patch is not materially different than that of users of levonorgestrel-containing OCs in women aged 39 years or younger. We cannot rule out some increase in the risk in women aged 40 years or older.