Differences in rates of switchbacks after switching from branded to authorized generic and branded to generic drug products: cohort study

Abstract

ObjectivesTo compare rates of switchbacks to branded drug products for patients switched from branded to authorized generic drug products, which have the same active ingredients, appearance, and excipients as the branded product, with patients switched from branded to generic drug products, which have the same active ingredients as the branded product but may differ in appearance and excipients.DesignObservational cohort study.SettingPrivate (a large commercial health plan) and public (Medicaid) insurance programs in the US.ParticipantsBeneficiaries of a large US commercial health insurer between 2004 and 2013 (primary cohort) and Medicaid beneficiaries between 2000 and 2010 (replication cohort).Main outcome measuresPatients taking branded products for one of the study drugs (alendronate tablets, amlodipine tablets, amlodipine-benazepril capsules, calcitonin salmon nasal spray, escitalopram tablets, glipizide extended release tablets, quinapril tablets, and sertraline tablets) were identified when they switched to an authorized generic or a generic drug product after the date of market entry of generic drug products. These patients were followed for switchbacks to the branded drug product in the year after their switch to an authorized generic or a generic drug product. Cox proportional hazard models were used to estimate hazard ratios and 95% confidence intervals after adjusting for demographics, including age, sex, and calendar year. Inverse variance meta-analysis was used to pool adjusted hazard ratios across all drug products.ResultsA total of 94 909 patients switched from branded to authorized generic drug products and 116 017 patients switched from branded to generic drug products and contributed to the switchback analysis. Unadjusted incidence rates of switchback varied across drug products, ranging from a low of 3.8 per 100 person years (for alendronate tablets) to a high of 17.8 per 100 person years (for amlodipine-benazepril capsules), with an overall rate of 8.2 per 100 person years across all drug products. Adjusted switchback rates were consistently lower for patients who switched from branded to authorized generic drug products compared with branded to generic drug products in the primary cohort (pooled hazard ratio 0.72, 95% confidence interval 0.64 to 0.81). Similar results (0.75, 0.62 to 0.91) were observed in the replication cohort.ConclusionSwitching from branded to authorized generic drug products was associated with lower switchback rates compared with switching from branded to generic drug products.

Comparative effectiveness of generic and brand-name medication use: A database study of US health insurance claims

“…Indeed, switching back to the brand-name product after a brand-name to generic switch is highly prevalent. In a previous study of the 8 drug products included in this study, we found that switching back to the brand-name product occurred at a rate of 8.9 per 100 person-years after a switch to a generic version, and a rate of 7.4 per 100 person-years after a switch to AG [ 31 ]. Switching back to the brand-name product when less expensive generic alternatives are available can result in unnecessary costs to patients and the healthcare system.…”

What is associated with increased side effects and lower perceived efficacy following switching to a generic medicine? A New Zealand cross-sectional patient survey

“… 5–7 Beliefs that the drug is less effective or causing side effects can also result in a significant number of patients switching back to the branded medication, resulting in less cost savings for the health system. 8 …”

Role of Authorized Generics in Postapproval Surveillance of Generic Drug Products

“…However, we observed similar findings for authorized generic vs. brand-name product initiators and no differences in outcomes between generic and authorized generic initiators, suggesting bias in the comparisons involving the generic or authorized generic products vs. the brand-name products. 5 In another claims-based study, Hansen and colleagues found similar or lower rates of subsequent outpatient visits, urgent care visits, emergency department visits, hospitalizations, and medication discontinuation in patients who switched from brand to generic products compared with those who switched from brand to authorized generic products. 9 These findings suggest that when differences in perceptions or socioeconomic status are controlled by using an authorized generic, the performance of brand-name and generic products may be similar with respect to claims-based clinical and health service use outcomes.…”

“…We found that, when authorized generics are marketed, their uptake and use is similar to that of other generic products. 5 Thus, many patients are using these products, even if they are unaware of it.…”