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Original Investigation
Health Care Reform
September 2016

Effect of Generic Competition on Atorvastatin Prescribing and Patients’ Out-of-Pocket Spending

Author Affiliations
  • 1Program on Regulation, Therapeutics, and Law (PORTAL), Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts

Copyright 2016 American Medical Association. All Rights Reserved. Applicable FARS/DFARS Restrictions Apply to Government Use.

JAMA Intern Med. 2016;176(9):1317-1323. doi:10.1001/jamainternmed.2016.3384

Importance  In November 2011, the cholesterol level–lowering medication atorvastatin calcium became available in the United States as a generic drug. However, only a single generic form (from a manufacturer that qualified for market exclusivity by challenging several of Pfizer’s patents) and an authorized generic form (a brand-name drug sold as a generic) were available for the first 180 days.

Objective  To describe trends in the prescribing of generic atorvastatin after expiration of market exclusivity for the brand-name medication and the effect on patients’ out-of-pocket spending.

Design, Setting, and Participants  A US population-based study used commercial claims data from the Optum Clinformatics research database (UnitedHealth Group) from December 1, 2010, to May 31, 2013. Participants were 1 968 709 adults with commercial insurance who had been prescribed 1 or more statins (13 285 223 statin prescriptions). An interrupted times series model was used to examine the effect of limited and full generic competition on brand-name and generic atorvastatin prescriptions. Data were analyzed from December 1, 2010, to May 31, 2013.

Exposures  Prescription of brand-name atorvastatin, generic atorvastatin, and authorized generic atorvastatin were distinguished using National Drug Codes.

Main Outcomes and Measures  Total number of prescriptions dispensed per month and out-of-pocket expenditures for a typical 30-day supply of 20-mg atorvastatin during the periods of brand-name availability only, limited generic competition (lasting 180 days after market exclusivity ended), and full generic competition.

Results  Of the 1 968 709 beneficiaries, 1 483 066 (58.8% male and 41.2% female; mean [SD] age, 55.6 [10.2] years) received a prescription for a single statin and were included in the analysis. The introduction of the first generic competitor was associated with a reduction in monthly brand-name atorvastatin fills by 20 896 prescriptions (level change, P = .001), an 18.1% change compared with the month preceding loss of exclusivity. Full generic competition reduced brand-name fills by 54 944 prescriptions (level change, P < .001), a 47.6% change relative to the month preceding loss of exclusivity. During the first 180 days of generic competition, no meaningful difference in monthly out-of-pocket spending was found between brand-name (median, $16.98; interquartile range [IQR], $8.76-$48.66) and generic (median, $19.98; IQR, $7.50-$54.90) atorvastatin. After full generic competition, estimated monthly out-of-pocket spending for generic atorvastatin (median $5.10; IQR, $3.36-$19.98) or authorized generic atorvastatin (median, $5.52; IQR, $3.48-$19.98) was substantially lower than that for brand-name atorvastatin (median, $30.00; IQR, $15.00-$91.38).

Conclusions and Relevance  Among patients with commercial health insurance, delays in generic uptake and high levels of out-of-pocket spending during the first 180 days after atorvastatin lost market exclusivity slowed changes in drug prescribing and decreases in patients’ out-of-pocket costs.