EVIDENCE SUMMARY
A 2013 systematic review studied the effect of dispensing a larger amount of pills on pregnancy rate, abortion rate, and overall cost to the health care system.1 Three of the 4 studies analyzed found lower rates of pregnancy and abortion, as well as lower cost despite increased pill wastage, in the groups that received more medication. The 1 study that didn’t show a significant difference between groups compared only short durations (1 vs 4 months).
The systematic review included a large retrospective cohort study from 2011 that examined public insurance data from more than 84,000 patients to compare pregnancy rates in women who were given a 1-year supply of oral contraceptives (12 or 13 packs) vs those given 1 or 3 packs at a time.2 The study found pregnancy rates of 2.9%, 3.3%, and 1.2% for 1, 3, and 12 or 13 months, respectively (P < .05; absolute risk reduction [ARR] = 1.7%; number needed to treat [NNT] = 59; relative risk reduction = 41%).
More pills lead to longer use of contraception
The systematic review also included a 2011 trial of 700 women starting oral contraceptives.3 It randomized them to receive a 7- or 3-month supply at their initial visit, then evaluated use of oral contraception at 6 months. All women were invited back for a 3-month follow-up visit, at which time the 3-month supply group would receive additional medication.
Fifty-one percent of the 7-month group were still using oral contraceptives at 6 months compared with 35% of the 3-month group (P < .001; NNT = 7). The contrast was starker for women younger than 18 years (49% vs 12%; NNT = 3). Notably, of the women who stopped using contraception, more in the 3-month group stopped because they ran out of medication (P = .02). Subjects in the 7-month group were more likely to have given birth and more likely to have 2 or more children.
A 2017 case study examined proposed legislation in California that required health plans to cover a 12-month supply of combined hormonal contraceptives.4 The California Health Benefits Review Program surveyed health insurers and reviewed contraception usage patterns. They found that, if the legislation passed, the state could expect a 30% reduction in unintended pregnancy (ARR = 2%; NNT = 50), resulting in 6000 fewer live births and 7000 fewer abortions per year.