Factors contributing to high levothyroxine doses in primary hypothyroidism: an interventional audit of a large community database.

Background: While few hypothyroid patients require more than the expected weight-related dose of levothyroxine, the underlying causes of larger-than-expected dosing requirements have not been studied in a single cohort. Our aim was to determine and quantify the multiple factors contributing to high-dose levothyroxine requirements in a cohort of patients with hypothyroidism.

Methods: The Grampian Automated Follow-Up Register (GAFUR) monitors around 17,500 hypothyroid patients.