Comparative Effectiveness of Generic and Brand-Name Statins on Patient Outcomes: A Cohort Study

By Joshua J. Gagne, PharmD, ScD; Niteesh K. Choudhry, MD, PhD; Aaron S. Kesselheim, MD, JD, MPH; Jennifer M. Polinski, ScD, MPH; David Hutchins, MBA, MHSA; Olga S. Matlin, PhD; Troyen A. Brennan, MD; Jerry Avorn, MD; and William H. Shrank, MD, MSHS
Annals of Internal Medicine, September 16, 2014

Background: Statins are effective in preventing cardiovascular events, but patients do not fully adhere to them.

Objective: To determine whether patients are more adherent to generic statins versus brand-name statins (lovastatin, pravastatin, or simvastatin) and whether greater adherence improves health outcomes.

Design: Observational, propensity score–matched, new-user cohort study.

Setting: Linked electronic data from medical and pharmacy claims.

Participants: Medicare beneficiaries aged 65 years or older with prescription drug coverage between 2006 and 2008.

Intervention: Initiation of a generic or brand-name statin.

Measurements: Adherence to statin therapy (measured as the pro- portion of days covered [PDC] up to 1 year) and a composite outcome comprising hospitalization for an acute coronary syndrome or stroke and all-cause mortality. Hazard ratios (HRs) and absolute rate differences were estimated.

Results: A total of 90 111 patients who initiated a statin during the study was identified; 83 731 (93%) initiated a generic drug, and 6380 (7%) initiated a brand-name drug. The mean age of patients was 75.6 years, and most (61%) were female. The average PDC was 77% for patients in the generic group and 71% for those in the brand-name group (P < 0.001). An 8% reduction in the rate of the clinical outcome was observed among patients in the generic group versus those in the brand-name group (HR, 0.92 [95% CI, 0.86 to 0.99]). The absolute difference was -1.53 events per 100 person-years (CI, -2.69 to -0.19 events per 100 person-years).

Limitation: Results may not be generalizable to other populations with different incomes or drug benefit structures.

Conclusion: Compared with those initiating brand-name statins, patients initiating generic statins were more likely to adhere and had a lower rate of a composite clinical outcome.

Primary Funding Source: Teva Pharmaceuticals.

From the Discussion:

In a head-to-head comparison, we found that patients initiating generic statins were more likely than those initiating brand-name statins to adhere to their prescribed treatment and had an 8% lower rate of a composite end point of cardiovascular events and death. Generic drug use has been widely recognized to reduce patient out-of-pocket costs and payer spending. Most persons in the United States are enrolled in prescription drug insurance programs with tiered benefits that require higher copayments for brand-name prescriptions than bioequivalent generic versions. Among patients in our study, the mean copayment for the index statin prescription was $10 for generic drug recipients and $48 for brand-name drug recipients. Our finding that adherence is greater with generic statins than with brand-name statins is therefore not surprising and is consistent with other studies that have shown a direct relation between higher copayments and lower adherence.

http://annals.org/article.aspx?articleid=1905128

This study further dispels the notion that more skin in the game leads to better outcomes.

The researchers prospectively examined 90,111 patients who received a new prescription for statin therapy and divided them into receiving generic (83,731 patients) versus name-brand (6380 patients) for the 3 statins that were generic at that time. They used propensity scores to “match” patients since they weren’t able to properly randomize patients to generic versus name-brand. They then measured adherence and outcomes and found the following:

  • 77% adherence in patients receiving generics versus 71% adherence in patients receiving name brand
  • 8% reduction in the rate of pooled clinical outcomes (stroke, acute coronary syndrome or all cause mortality) for patients receiving generics
  • They note that the out of pocket costs to fill the generic was 10 dollars and the branded was 48 dollars

They basically conclude that patients who have to pay more for their medications are less likely to be adherent, and that the difference in clinical outcomes occurred as a direct result of the increased cost, leading to poorer adherence and consequently more strokes/ACS/death.

There’s lots in here:

  • Generics work
  • Generics are cheaper
  • Relatively small differences in adherence can lead to substantial clinical outcomes (ie, perhaps we should focus on improving adherence to prescribed therapies)

But I think that the biggest take-home is that if patients have to pay more for medications, they will not take them and then they will die. Ergo, shifting costs to patients leads to more death.

Philip Verhoef, MD, PhD is Clinical Instructor of Medicine at The University of Chicago Medicine, a member of the PNHP Advisory Board, and co-president for PNHP-Illinois.