Evidence Of Bias Against Adoption Of Anti-Obesity Pharmacotherapies

Abstract

Background Approximately half of adults in the U.S. fit the criteria for use of anti-obesity pharmacotherapy, but only 2% of those receive such treatment. This is in sharp contrast to the 8.4% of adults diagnosed with diabetes, with 86% of those receiving anti-diabetes pharmacotherapy. In 2012-2014, the first medications in 13 years were FDA approved for long-term management of obesity. In 2013-2014, the newest class of anti-diabetes pharmacotherapy, subtype 2 sodium-glucose transport protein inhibitors (SGLT2s), were FDA approved. Methods A retrospective analysis of extracted data from the IMS Health National Prescription Audit™ and Xponent™ assessed adoption rates of anti-obesity pharmacotherapies and SGLT2s using univariate linear regressions. Volumes of new and continuing prescriptions were compared using ratio analyses. Prescriber groups were compared by descriptive proportions according to prescription volumes, medical specialty, geographic region, and prescriber-drug overlap. Results The entire anti-diabetes market was 15 times the entire anti-obesity market. The anti-obesity market share was: 74.0% phentermine and 18.6% new anti-obesity pharmacotherapies. The mean increase in prescriptions per month were: 25,259 for SGLT2s (95% CI 23,133-27,383 p<0.0001), 5,154 for new anti-obesity pharmacotherapies (95% CI 4,800-5,507 p<0.0001), and 2,718 for phentermine (95% CI 1,345-4,089 p=0.0003). Medical specialties prescribing the majority of the analysis medications were Family Medicine/General Practice and Internal Medicine. Endocrinology had the highest prevalence of prescribers of any sub-specialty. Conclusions The adoption rate of SGLT2s was nearly exponential, while the adoption rate of new anti-obesity pharmacotherapies was linear. Considering the relative prevalence of obesity to diabetes and that obesity is a major cause of diabetes, these results are paradoxical and suggest biases against the prescribing of anti-obesity pharmacotherapies. The under-prescribing of anti-obesity pharmacotherapies is widely acknowledged, but this is the first prescription data to demonstrate its extent in the U.S.