The Economic Impact of Levothyroxine Dose Adjustments: the CONTROL HE Study

BACKGROUND In general, hypothyroidism can be adequately treated with a consistent daily dose of levothyroxine. However, the need for levothyroxine dose adjustments is frequent in clinical practice. The extent to which levothyroxine dose adjustments increase the utilization of healthcare resources has not previously been described in the clinical literature. OBJECTIVE The primary objective of our study was to measure the effect of levothyroxine dose adjustments in terms of their utilization of healthcare resources including direct and indirect costs. A secondary goal was to identify any differences in patient characteristics that may be responsible for levothyroxine dose adjustments. METHODS A retrospective medical chart review was conducted among patients of selected healthcare providers in the USA. Patients who were recently started on levothyroxine therapy (<6 months) were excluded to avoid situations that were more likely attributable to treatment initiation than inadequate therapeutic effect. Trained nurses extracted data from patient charts and electronic medical record systems for review. We analyzed the cost of resources consumed by the frequency of levothyroxine dose changes over 24 months: 0 dose changes (no dose adjustment group); one dose change, two dose changes, three or more dose changes (≥1 dose adjustment group). RESULTS The study included 454 patients. Overall estimated resource utilization was higher per patient in the ≥1 dose adjustment group (US$5824) vs. the no dose adjustment group (US$3166) during the 24-month study period. When direct and indirect costs were combined, overall costs of care were greatest in patients requiring three or more dose adjustments (US$8220/patient). Patients in this cohort incurred 2.5-fold greater total costs compared with patients requiring no dose adjustments (US$8220 vs. US$3166). Among the 58 patients in the group requiring three or more dose adjustments, mean direct medical costs were significantly higher than in the patients requiring no dose adjustments (US$6387 vs. US$2182). Patients with at least one dose adjustment experienced a 40.3% increase in lost productivity vs. patients who had no dose adjustments (US$1381 vs. US$984). Loss of productivity was highest among patients with three or more levothyroxine dose adjustments. Among this cohort, there was an 86.4% increase in lost productivity vs. patients who had no levothyroxine dose adjustments (US$1833 vs. US$984). CONCLUSIONS Patients experiencing multiple levothyroxine dose adjustments were shown to consume more healthcare resources, resulting in higher costs than those who required no dose adjustments. Each care episode contributed to lost time and wages with total estimated lost productivity escalating with increasing levothyroxine dose adjustments over a 24-month period.