Background: Since metformin (MET), approved for treatment of type 2 diabetes (T2D), is the most commonly used oral anti-hyperglycaemic agent in youths MET prescriptions (Rx) could be used as a proxy for T2D burden in these populations. However, the extent of off-label use of MET in paediatrics is not well studied.
Objective and hypotheses: Estimate the annual prevalence of ≥1 MET Rx among youths and calculate proportions with concomitant diagnoses of T2D and others.
Method: Patients, 1020 years old, from a large US claims database, Truven Health MarketScan, with ≥1 metformin Rx during 20092013 with ±6 months continuous enrollment from the index MET Rx date were eligible. Prevalence proportions and 95% CI were calculated using Poisson regression. Diagnosis and procedure codes within ±6 months of the index MET Rx were used to identify T2D and other medical conditions.
Results: During 20092013, 22 387 patients (80% females and 83% 1520 years of age) had ≥1 MET Rx. Annual prevalence proportions were consistent across years and were 0.39 (0.36, 0.41) and 1.13 (1.27, 1.34) P=1.000 for 1014 and 1520 age groups, respectively, in 2013. Among MET Rx patients, mutually-exclusive proportions with concomitant diagnoses were PCOS alone (23%), obesity alone (12%), PCOS and obesity (7%), T2D alone (10%), T2D with PCOS/obesity, or both (8%), or other diagnoses (40%). Sensitivity analyses on the subset of patients with ≥2 MET Rx within a 6-month window showed similar results.
Conclusion: Within a large US claims database, only a minority of patients (18%) with ≥1 or ≥2 MET Rx had a diagnosis of T2D; the vast majority (~80%) had diagnoses other than T2D, suggesting that off-label use of MET is very common in youth in the USA. Therefore, the use of metformin Rx as a proxy for T2D in youth may grossly overestimate the burden of the disease.
Declaration of interest: All authors are employees of Merck & Co., Inc., Kenilworth, NJ, USA.
Funding: The study was funded by Merck & Co., Inc., Kenilworth, NJ, USA.
01 - 03 Oct 2015
European Society for Paediatric Endocrinology