Brand-name thyroid hormone medication prescriptions decreased from 2007 to 2016, with the strongest predictor associated with brand-name usage being prescriber specialty, according to study results published in The Journal of Clinical Endocrinology & Metabolism.
Researchers of this retrospective cross-sectional study analyzed patterns of brand-name and generic thyroid hormone medication prescriptions using the OptumLabs Data Warehouse. Patient characteristics, such as demographics, socioeconomic status, and insurance category, and prescriber specialty, including endocrinology, family practice, internal medicine, and obstetrics and gynecology, were categorized to evaluate potential predictors.
From 2007 to 2016, there were 96,354,600 thyroid medication prescriptions filled for 4,228,174 patients. There was a 30.4% increase in prescriptions filled and a 64.7% increase in new patients filling a thyroid hormone prescription from 2007 to 2016. Generic levothyroxine accounted for 73.6% of prescriptions filled and brand-name levothyroxine accounted for 23.4% of prescriptions filled. There was an increase in generic prescriptions from 59.8% of all fills in 2007 to 84.9% in 2016 (P <.001).
Generic thyroid medications were consistently prescribed more frequently in patients with Medicare Advantage and Medicare Part D insurance (P <.001). Overall, patient predictors of thyroid medication usage were that older adults more frequently used generic thyroid medication, women more frequently used brand-name thyroid medication, and prescriptions from endocrinologists were more frequently for brand-name thyroid medications. The largest association in the multivariable analysis was between brand-name thyroid medication and having an endocrinologist prescribe the medication for both commercial (OR, 3.28; 95% CI, 3.25-3.32) and Medicare Advantage insurance (OR, 4.32; 95% CI, 4.21-4.44).
Some limitations of this study included inability to deduce if the patient, prescriber, or pharmacist made the request for the generic medication. Additionally, the characteristics of patients and prescriber types came from administrative claims and not research reports, the specific condition for the medication prescription was not considered, and patients’ out-of-pocket costs were not included.
“Our findings provide national estimates of generic thyroid hormone replacement therapy use and can be used to inform efforts to ensure that patients are using the lowest-cost available therapies when appropriate,” concluded the researchers.
Some authors declared associations with pharmaceutical companies. Please refer to original reference for a complete list of authors’ disclosures.
Ross JS, Rohde S, Sangaralingham L, et al. Generic and brand-name thyroid hormone drug use among commercially-insured and Medicare beneficiaries, 2007-2016 [published online January 25, 2019]. J Clin Endocrinol Metab. doi:10.1210/jc.2018-02197