Content area
Full Text
Introduction
About 104 million women worldwide use oral contraceptives. 1 In most countries various types of pills are available, and studies have shown an increased risk of venous thromboembolism with the use of combined oral contraceptives. 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 This risk differs according to type of progestogen and decreases with both duration of use and decreasing oestrogen dose.
The optimal choice of oral contraceptives must also take into account the risks of stroke and myocardial infarction. Few studies have examined this relation, and those that are available have reported conflicting results. 19 20 21 22 23 24 25 26 27 28 29 30 31 The impact and magnitude of the arterial risk according to dose of oestrogen (ethinylestradiol, 20 [micro]g v 30-40 [micro]g) have not been established for all progestogens. In France, eight combinations were available and reimbursed by national health insurance during the study period (table 1 ). They differed according to type of progestogen (norethisterone, levonorgestrel, desogestrel, gestodene, norgestrel) and dose of oestrogen (20 [micro]g to 50 [micro]g).
Combined oral contraceptive | Generation of progestogen | Introduction to market | Start of reimbursement by health insurance | |
Progestogen type | Oestrogen* dose | |||
Norethisterone | 35 [micro]g | First | 1982 | June 1984 |
Norgestrel | 50 [micro]g | Second | 1973 | February 1975 |
Levonorgestrel | 30-40 [micro]g | Second | 1974 | May 1976 |
Levonorgestrel | 20 [micro]g | Second | Apr-10 | April 2010 |
Desogestrel | 30 [micro]g | Third | 1984 | September 2009 |
Desogestrel | 20 [micro]g | Third | 1988 | January 2010 |
Gestodene | 30 [micro]g | Third | 1988 | November 2010 |
Gestodene | 20 [micro]g | Third | 1995 | November 2010 |
*Ethinylestradiol.
We assessed, under real life conditions in France, the absolute and relative risk of pulmonary embolism, ischaemic stroke, and myocardial infarction associated with the eight reimbursed oral contraceptives (including levonorgestrel with 20 [micro]g oestrogen) according to type of progestogen and dose of oestrogen. The objective was to identify the combination associated with the lowest risk of venous and arterial thromboembolism.
Methods
This study was based on an observational historical population cohort comprising all women aged 15-49 years, living in France, with at least one reimbursement for oral contraceptives between July 2010 and September 2012.
Data source
We identified women in the French national health insurance database (SNIIRAM) linked to the French hospital discharge database (Programme...