Table 2.
Characteristics of the included studies.
| Author, year | Study design | Sample size | Population characteristics: mean age, mean BMI, % smokers, % of family history of VTE | Name of COC | Event/person time – Event/number of participant a | Funding | Study quality (NOS scale) |
|---|---|---|---|---|---|---|---|
| Lidegaard, 2013 (35) | Prospective study | Women on E2-based COC: n=5,202 Women on synthetic estrogens: n=305,171 |
NR | E2-based COC: E2-DNG Synthetic estrogens: EE-LNG |
E2-based COC: - 5/5,202 Synthetic estrogens: - 186/305,171 |
NR | Not assessed |
| Reed, 2021 (13) | Prospective study | E2-based COC: - n=44,559 Synthetic estrogens: - n=49,754 |
mean age: 30.1 mean BMI: 23.3 21% of smokers 2.4% of family history of VTE |
E2-based COC: - E2-NOMAC Synthetic estrogens: - EE-LNG |
E2-based COC: - 12/48,846 Synthetic estrogens: - 25/62,337 |
Merck Sharp and Dohme, a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA, and Theramex Ireland Limited, Dublin, Ireland | 9/9 stars |
| Schink, 2022 (25) | Case-control study | Women on E2-based COC: - n=35 Synthetic estrogens: - n=2,512 |
VTE cases: mean age 17.6 20.6% obese 4.12% of smokers 10.6% of family history of VTE Controls: mean age 17.6 6.67% obese 2.54% of smokers 1.43% of family history of VTE |
E2-based COC: - E2-DNG Synthetic estrogens: - EE-LNG |
E2-based COC: - 6/101 Synthetic estrogens: - 1,139/12,338 |
Funded by the Federal Institute for Drugs and Medical Devices (Bundesinstitut f̈r Arzneimittel und Medizinprodukte, BfArM) | 9/9 stars |
| Heikinheimo, 2022 (24) | Nested Case-control study | E2-based COC: - n=129 Synthetic estrogens: - n=510 |
mean age - not reported mean BMI - not reported % of smokers - not reported % of family history of VTE - not reported |
E2-based COC: - E2/DNG - E2/NOMAC Synthetic estrogens: - EE/DSG - EE/GSD - EE/DRSP - EE/norelgestromin - EE/etonogestrel |
E2-based COC: - 25/129 Synthetic estrogens: - 158/510 |
Erkko Foundation; Yrjö Jahnsson foundation (ET); Avohoidon tutkimussäätiö & Helsinki University Library |
7/9 stars |
| Bauerfeind, 2024 (23) | Prospective study | E2-based COC: - n=11,616 Synthetic estrogens: - n=58,693 |
mean age 27.1 mean BMI 24.2 23% of smokers 3.1% of family history of VTE |
E2-based COC: - E2-DNG Synthetic estrogens: - EE-LNG - oCOC |
E2-based COC: - 11/17,932 Synthetic estrogens: - 99/107,586 |
Unconditional grant from Bayer AG, Germany | 9/9 stars |
a
Event/person time reported for prospective studies – Event/number of participants reported for case-control studies.
b
Only confirmed VTE were considered as events.
NR, Not Reported; COC, Combined Oral Contraceptives; BMI, Body Mass Index.