Risk of venous thrombosis in users of hormonal contraceptives in German gynaecological practices- a patient database analysis

Purpose: Recent studies showed differences in the risk of venous thrombosis between different combined hormonal contraceptives. Database studies comprising large cohorts can add relevant aspects in a daily clinical practice manner. The purpose of this study was the evaluation of different progesterone derivatives in combination with ethinylestradiol on the risk of venous thrombosis in Germany. Methods: Computerized data from 68,168 contraceptive users in gynaecological practices throughout Germany (Disease Analyzer database) were analysed. The adjusted Odds ratios for risk of thrombosis were estimated in users of different OC formulations relative to users of levonorgestrel containing preparations. Results: 38 (0.06%) of 68,168 contraceptive users, had a recorded diagnosis of thrombosis within 365 days after first prescription. The adjusted risk was 1.95 for desogestrel (CI: 0.52 – 7.29), 2.97 for dienogest (CI: 0.96 – 9.24), 1.57 for drospirenone (CI: 0.46 – 5.38), 2.54 for chlormadinone (CI:0.72 – 9.04) and 3.24 for norgestimate (CI: 0.59 – 17.75) compared to levonorgestrel. None of those findings did reach statistical significance. The maximum absolute increase versus levonorgestrel was 6 cases per 10000 women (n.s.). Conclusion: The study somewhat confirms recent results showing an increased risk of 3 rd and 4th generation OC versus levonorgestrel containing products, but also confirms the low incidence rates of thrombosis in OC users.