Background: Hormonal contraceptive use is generally characterized by poor adherence and relatively high discontinuation. This study investigated whether specific hormonal contraceptive formulations and/or delivery systems might be correlated with discontinuation of contraception.
Study design: This was a retrospective descriptive analysis within a large administrative claims database. The sample included women aged 15-40 years with a pharmacy benefit and at least one new hormonal contraception prescription during the study period and no prescription in the previous 6 months. Filled contraceptive prescriptions were grouped into several categories of delivery system, dosage, progestin type and monophasic vs. triphasic formulations. In each, a baseline number of women was established who filled a first prescription for a contraceptive formulation in the specified category. Then, the percentage of these women who filled a prescription for a contraceptive in the same category within 3 months' time was determined. Continuation or change rates were compared within each group.
Results: Oral contraceptives (OCs) were the least likely to be discontinued at 3 months; injectables were the most likely. OC formulations associated with increased risk of discontinuation (odds ratios above 1.3 representing a 5% or higher increased discontinuation) included very-low-dose (20-25 mcg ethinyl estradiol) pills containing norethindrone acetate or norgestimate, as compared to a preparation with the same progestin type but with a higher dose of estrogen. Desogestrel and norethindrone-containing triphasics were more likely to be discontinued than other triphasic progestins. OC formulations with desogestrel and norethindrone/norethindrone acetate were more likely than formulations with other progestins to be discontinued overall.
Conclusions: This investigation in a sample of nearly 250,000 women suggests possible associations between discontinuation of hormonal contraception and factors such as estrogen dosing, progestin type and changes in dosage during the cycle. Identification of factors correlated with contraceptive discontinuation may inform management and improve adherence.