Case Presentation
Nicole is a 39-year-old woman, married with 2 children. She used a combined oral contraceptive for 12 years prior to the birth of her 2 children. While raising her children, she and her husband relied on the sponge, condoms, and ‘safe sex’ to prevent pregnancy since she was so busy she did not think she would be able to remember to take her contraceptive pill every day as indicated. At this time, she indicates she has completed her family and recently resumed her career as a sales manager at a busy office supply store after her youngest child started first grade.
She reports that before starting her family, she enjoyed the effectiveness and convenience of a combined oral contraceptive and would like to resume using it again but is concerned that it might cause weight gain. Nicole reports that she gained some weight with both of her pregnancies and has not been able to lose the excess weight. Nicole’s physical exam and history reveals that she has a body mass index of 31 and she smokes about a pack to a pack and a half of cigarettes per day. Nicole also reports that she had a ‘blood clot’ in the calf of her left leg while pregnant with her second child. This was successfully treated with heparin with no notable sequelae.
Decision aids increase individual’s involvement in the decision-making process and are associated with a higher likelihood of making informed, value-based decisions. Decision aids compared with usual care have been shown to achieve greater knowledge, lower levels of decisional conflict related to feeling uninformed, decrease decisional conflict related to personal value systems, and increase involvement in the decision-making process. Decision aids that include numeric information about probabilities such as absolute risk are more likely to results in more accurate risk perceptions. The following decision aid may help you to discuss the risks and benefits of hormonal contraception with your adolescent patients.
- Clarify the situation
- Provide information on benefits and harms
- Clarify patient values
- Screen for implementation problems
As you review Nicole’s physical exam and history, you take time to clarify the unique aspects of Nicole’s personal health situation as well as assess her knowledge and concerns about combined oral contraceptives. You clarify that combined oral contraceptives are a very safe and effective method of contraception for many women with very low rates of unintended pregnancy when taken as directed. However, oral contraceptives are associated with significantly higher rates of some adverse events such as VTE for women with additional risk factors for VTE. You explain to Nicole that her personal history of VTE as well as the fact that she is 39, currently overweight, and smokes cigarettes are factors that increase her risk of VTE.
You review data from a recent study that summarizes the risk per 10,000 women-years for VTE among users of oral contraceptives by age and body mass index. You explain that the risk increases for women as they age and also for those with higher body weights rising to 33.0 per 10,000 women-years among women aged 25 to 39 years or older with a body mass index of 30 or higher. You explain that “the chance of having a serious problem like heart attack, stroke, or blood clot is greater for women using hormonal contraceptives than for women who don’t use them. This is especially true if they are overweight, smoke, or have had a blood clot before.” In the absence of additional risk factors for VTE, the absolute risk of VTE associated with oral contraceptives decreases to 18.9 per 10,000 women-years among women in Nicole’s age and weight group.
You further explore Nicole’s perceptions about using a combined oral contraceptive after providing her with information about the risk associated with this method for a woman with her medical history by asking: “Do you feel comfortable resuming use of a combined oral contraceptive after learning that they are associated with an increased risk of VTE in women similar to you who have a personal history of VTE, are overweight, and smoke cigarettes.” Nicole indicates that she was unaware of the risk of VTE associated with the use of combined oral contraceptives She indicates that she would like to explore other contraceptive options with a more favorable safety profile but equivalent effectiveness. You review the safety and efficacy of intrauterine contraceptives including the Copper T 380A and the LNG IUS, noting that the LNG IUS is not associated with an increased risk of VTE. Nicole decides to switch to the LNG IUS and schedules an appointment for insertion in 2 weeks as well as a follow-up appointment 1 month following insertion to ensure that the LNG IUS is still in place and there are no signs of infection.
References
- Evidence-Based Emergency Medicine at the New York Academy of Medicine. Glossary of Terms: Absolute risk and its reduction. Available at: http://ebem.org/definitions.html. Accessed 19 July 2012.
- Grimes DA, Schulz KF. An overview of clinical research: the lay of the land. Lancet. 2002;359:57-61.
- Grimes DA, Schulz KF. Bias and causal associations in observational research. Lancet. 2002;359(9302):248–252.
- Mills A. Combined oral contraception and the risk of venous thromboembolism. Hum Reprod. 1997;12(12):2595-2598.
- Morton RF, Hebel JR, McCarter RJ. A Study Guide to Epidemiology and Biostatistics, 4th Edition. Aspen Publishers, Inc. Gaithersberg, MD; 1996.
- O’Connor A, Legare F, Stacey D. Risk communication in practice: the contribution of decision aids. BMJ. 2003;327(7417):736-40.
- Rabe T, Luxembourg B, Ludwig M, et al. Contraception and thrombophilia—A statement from the German Society for Gynecological Endocrinology and Reproductive Medicine (DGGEF e.V.) and the Professional Association of German Gynaecologists (BVF e.V). J Reproduktionsmed Endokrinol. 2011;8(special issue 1):178-218.
Definitions of Risk and Contraceptive Choice
