An analysis of data from over 3.5 million patients found comparable clinical outcomes among patients who initiated generics vs those who were treated with brand-name drugs for chronic conditions such as diabetes, hypertension, osteoporosis, depression and anxiety. The study findings were published in PLOS Medicine.
Using 2 large US insurance databases (Optum Clinformatics Data Mart [years 2004 to 2013 and Truven MarketScan [2003 to 2015]), the study authors analyzed claims data to compare clinical outcomes in patients treated with brand and generic drugs. Authorized generics (AG) – identical in chemical composition and appearance to brand-name drugs but marketed as generics – were used as a control group to address negative perception bias.
Outcomes were compared between generic and AG users, generic users and brand-name users, and AG users and brand-name users. The 8 products included in the analysis were amlodipine, amlodipine/benazepril, quinapril, alendronate, calcitonin, sertraline, escitalopram, and glipizide.
Results showed that when brand-name and generic products were compared (1,313,161 matched pairs), no differences in clinical outcomes were observed with alendronate and calcitonin (non-vertebral fracture endpoint), glipizide (insulin initiation due to poor glycemic control), or quinapril (hospitalization due to MI, ischemic stroke; coronary revascularization procedure). In fact, a lower risk of the composite cardiovascular endpoint was noted with generics vs brand-name products for amlodipine and amlodipine/benazepril (hazard ratio [HR] 0.91; 95% CI, 0.84–0.99 and HR 0.84; 95% CI 0.76–0.94, respectively).
For the comparison of AGs vs generics, out of 16 clinical endpoints, only 4 were associated with different outcomes; 3 favored generics and 1 favored AGs (switching from amlodipine brand-name (HR 0.92; 95% CI, 0.88–0.97).
For escitalopram and sertraline, higher rates of psychiatric hospitalization (clinical endpoint) were noted in patients taking generics (HR 1.05; 95% CI, 1.01–1.10) and HR 1.07; 95% CI, 1.01–1.14, respectively), and AGs (HR 1.06; 95% CI, 0.98–1.13 and HR 1.11; 95% CI 1.05–1.18, respectively), compared with those who initiated brand-name products. “[T]he differences observed between brand and generic users in these outcomes are likely explained by either residual confounding or generic perception bias,” the authors explained.
While the authors acknowledged that the study had several limitations (potential residual confounding, inability to evaluate surrogate outcomes), they concluded that “these results could help in promoting educational interventions aimed at increasing patient and provider confidence in the ability of generic medicines to manage chronic diseases.”
For more information visit Plos.org.