Purpose: To evaluate whether the thromboembolic risk and contraceptive effectiveness of NOMAC-E2 observed in the PRO-E2 study can be extended to each participating country, as lifestyle, cardiovascular risk factors and prescribing habits may differ geographically. This analysis was performed on the PRO-E2 Italian subpopulation, where smoking habit and women over 35 years were more prevalent compared with the overall study population.
Materials and methods: Data from NOMAC-E2 or levonorgestrel-containing COCs (COCLNG) new users were descriptively analysed. Incidence rates of thrombosis (events/10,000 women-years [WY]) and the Pearl Index (pregnancies/100 WY) were calculated.
Results: Overall, 11,179 NOMAC-E2 and 8,504 COCLNG users were followed up to 2 years (34,869 WY). The NOMAC-E2 cohort included more women over 35 vs. COCLNG (37.7% vs. 31.8%; p = 0.001). A comparable low risk of combined deep venous thrombosis of lower extremities (DVT) and pulmonary embolism (PE) was observed in NOMAC-E2 (1.7/10,000 WY; 95% CI: 0.21-6.2) and COCLNG users (6.6/10,000 WY; 95% CI: 2.4-14.4). Similar results were obtained by considering all thromboembolic events (VTE). Unintended pregnancies did not differ between NOMAC-E2 (0.12/100 WY; 95% CI: 0.06-0.21) and COCLNG (0.15/100 WY; 95% CI: 0.08-0.26) cohorts.
Conclusion: Despite the higher age and tobacco use, findings from the Italian subpopulation were broadly consistent with overall PRO-E2 results, confirming a similar low thromboembolic risk and high contraceptive effectiveness of NOMAC-E2 and COCLNG.
Short condensation: This subgroup analysis of the PRO-E2 study provides comprehensive epidemiological data on the use of combined oral contraceptives in a large Italian cohort, with a higher prevalence of women over 35 years and smokers. The study confirms the low thromboembolic risk and high contraceptive effectiveness of NOMAC-E2 pill.
Keywords: Italy; NOMAC-E2; levonorgestrel; nomegestrol acetate; oestradiol; unintended pregnancy; venous thromboembolism.