Objective: To compare pregnancy rates among women provided a 12-month supply or less than a 12-month supply of short-acting hormonal contraceptives.
Study design: This retrospective cohort study examined data from an integrated health plan in California, collected about people aged 10-50 years, who filled at least one contraceptive prescription between January 2017 and September 2018. We examined outcomes following index contraceptive prescriptions for up to 15 months, end of membership, initiation of a long-acting contraceptive, or death, whichever occurred first. We compared rates per 100 person years of observation of: pregnancy, receipt of emergency contraception (EC), and contraceptive refills more than 12 months after the index prescription. We used multivariable logistic regression to control for demographics and baseline clinical variables when comparing provision of a 12-month to a smaller supply.
Results: We identified 1689 members who received a 12-month supply of short-acting hormonal contraception and 352,624 women who received less than a 12-month supply. Those who received a 12-month supply were less likely to receive EC (1.3 vs 2.1 per 100 person years, p = 0.04) or have documentation of pregnancy (1.7 vs 2.7 per 100 person-years, p = 0.02), and more likely to refill the contraceptive more than 1 year after the index prescription (99.4% vs 63.9%, p < 0.01). Among new starts, the adjusted odds ratio (OR) of pregnancy was 0.50 (95% CI 0.27-0.94) among women who received a 12-month supply vs. those were not.
Conclusion: Members of an integrated healthcare system who received a 12-month supply of short-acting hormonal contraceptives are less likely to become pregnant within the following year.
Implications: Offering a 12-month supply of short-acting hormonal contraceptives may reduce rates of undesired pregnancy.
Keywords: Emergency contraception; Extended supply of contraception; Pregnancy; Short-acting hormonal contraceptives; Women.
Copyright © 2021. Published by Elsevier Inc.