Purpose: About half of all pregnancies in the US are unintended. Emergency contraceptive pills are 89 percent effective in preventing pregnancy if taken within 72 hours of unprotected sex. In August 2006, the FDA announced that Plan B, commonly referred to as the “morning after pill”, would be made over-the-counter (OTC) for women 18 and older. Women age 17 and under would still require a prescription from a physician. Prior to the legislation, nine states had pharmacy access legislation allowing a woman of any age to purchase Plan B from a pharmacist. This study assess whether by increasing access to Plan B, we observe a decrease in number of abortions and an increase in sexually transmitted infections (STIs). The latter would occur if increased access to Plan B increases the frequency of unprotected sex or causes women to abandon effective forms of birth control.
Method: Data source is the Thompson MarketScan Database 2005-2007 with sample size of 1,685,669 unique females ages 15-44 in each year. STIs and abortion identified using ICD-9 codes and CPT4 procedure or supplies codes provided in outpatient claims data. Using a pre-post design with an early adopter control group, I identify the effect of the FDA ruling on two outcomes of interest: STIs and abortion using a difference-in-difference estimator allowing for age trends. A log-link model and logit regression is specified and bootstrapped standard errors around the average marginal effect are obtained. Cost-effectiveness analysis is used to compare medical costs across alternatives: physician visit (time and monetary) and prescription cost, retail cost of OTC pill, and abortion in the event of unintended pregnancy.
Result: Making Plan B OTC resulted in 416 additional STIs per 100,000 women age 15-44, 95% CI [258, 575] and 108 fewer abortions per 100,000 women age 15-29, 95% CI [54, 171]. The relative risk of STI among women in early adapter states compared to those in late adapter states is 1.045, 95% CI [10.014, 1077]. Women 15-29 in the early adopter states have a RR of abortion over the laggard states of 0.898, 95% CI [0.827, 0.976].
Conclusion: Physicians should counsel women on safer sex practices and pharmacists could offer information on safer sex practices with purchase of Plan B.
Candidate for the Lee B. Lusted Student Prize Competition