Generic Substitution Rates of Oral Contraceptives and Associated Out-of-Pocket Cost Savings Between January 2010 and December 2014

Over one-quarter of women in the United States of reproductive age have used oral contraceptives (OCPs).¹ While most OCPs are available as generics, utilization of generic OCPs and associated cost savings is poorly understood.² Amid a shift toward value-based care and current debates over contraceptive coverage, we describe generic OCP utilization and out-of-pocket cost savings by switching from brand to generic OCPs in a nationally representative sample.

We used the January 2010 to December 2014 Medical Expenditure Panel Survey (MEPS), a nationally representative survey conducted by the Agency for Healthcare Research and Quality to examine usage and cost of OCPs.³ The MEPS has been used to estimate savings from generic substitution.^2,4 Oral contraceptive prescribing events were categorized as brand or generic by cross referencing the national drug code (NDC) in MEPS with the US Food and Drug Administration (FDA) NDC directory.⁵ For each brand entry, the availability of a generic option was determined by searching the FDA Orange Book database.⁶ We excluded entries that were prescribed to individuals older than 55 years, did not have a valid NDC, or reported no total cost. This research was not performed on human participants, so institutional review approval was not necessary.

Average per person per year (PPPY) generic and brand out-of-pocket costs were determined among individuals prescribed only generic or only brand OCPs in a given year. The 4% of individuals who received brand and generic OCPs during a given year were excluded to prevent switching OCPs from confounding PPPY cost. We estimated the out-of-pocket savings of switching from brand to generic OCPs assuming the same utilization pattern of generic drugs and constant prices, by calculating the weighted mean difference PPPY between brand-name drug costs and our market basket of generic drugs. The weight of each individual is assigned in the MEPS data set. All expenditures were converted to 2014 dollars by using Bureau of Labor Statistics medical price index.

The study population consisted of 19 944 OCP prescribing events for 3086 individuals from January 2010 to December 2014 who represent 49.8 million women nationally. Median (interquartile range) age was 28 (22-35) years; white women comprised 75.6% (n = 2334) of the population, and Hispanic women comprised 19.7% (n = 609) (Table).

Generic OCP prescribing increased from 73% in 2010 to 82% in 2014. Brand OCPs represented a disproportionate proportion of total OCP expenditures, accounting for 24% of all prescriptions between 2010 and 2014 but 42% of total expenditures (Figure). Of all brand OCP prescriptions, 97.4% had generic options available.

For generic OCPs, average out-of-pocket cost PPPY was $59.53 (total PPPY cost, $163.24). For brand OCPs, average out-of-pocket cost PPPY was $117.15 (total PPPY cost, $427.06). Brand prescriptions had longer pill days PPPY than generics (289 d [95% CI, 273-306] vs 244 d [95% CI, 234-255]; P < .001). The percent of OCP prescriptions with no copay increased from 14.4% between 2010 and 2011 prior to the Affordable Care Act (ACA) contraceptive mandate to 47.0% between 2012 and 2014 post-ACA contraceptive mandate (P < .001). Assuming constant prices, substituting generic OCPs for brand when generic options were available would have saved $751 million in out-of-pocket costs during the study years.

That we know of, this is the first study to date to examine OCP generic substitution rate and estimate potential savings of switching from brand to generic OCPs using a nationally representative sample in the post-ACA landscape. While brand OCP prescribing has declined, its share of total spending has not decreased, reflecting a possible increase of the relative price of brand OCPs to generic OCPs. The potential out-of-pocket savings from prescribing generic instead of brand OCPs are significant.

Our study is limited by a lack of data on off-label prescribing of OCPs and pharmaceutical rebates, which are not accounted for in the MEPS. These results underscore the foregone opportunities of generic prescribing as a strategy to reduce health care costs and highlight the challenges in promoting generic OCP prescribing.

Corresponding Author: Vineet M. Arora, MD, MAPP, Section of General Internal Medicine, Department of Medicine, University of Chicago Medicine, 5841 S Maryland Ave, MC 2007, Chicago, IL 60637 (varora@medicine.bsd.uchicago.edu).

Accepted for Publication: November 13, 2017.

Published Online: January 16, 2018. doi:10.1001/jamainternmed.2017.7849

Author Contributions: Dr Arora and Mr Chee had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

Study concept and design: Chee, Zhang, Ngooi, Arora.

Acquisition, analysis, or interpretation of data: All authors.

Drafting of the manuscript: Chee, Zhang, Arora.

Critical revision of the manuscript for important intellectual content: Zhang, Ngooi, Moriates, Shah, Arora.

Statistical analysis: Chee, Zhang, Ngooi, Arora.

Obtained funding: Arora.

Administrative, technical, or material support: Zhang, Ngooi, Arora.

Study supervision: Zhang, Ngooi, Moriates, Arora.

Conflict of Interest Disclosures: Dr Zhang, Ms Ngooi, Dr Moriates, Dr Shah, and Dr Arora all receive funding from a US Food and Drug Administration grant to improve prescription of generic drugs.

Funding/Support: Mr Chee receives funding from the National Institutes of Health (grant No. T35AG029795).

Role of the Funder/Sponsor: The funder/sponsor had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.