Incidence and risk factors for early thyroxin supplementation therapy after hemithyroidectomy for benign conditions in Europe. A Eurocrine® registry-based study.

The incidence and risk factors of hypothyroidism after hemithyroidectomy (HT) remain poorly defined. Regarding its management, national or local policies may influence on early (first visit) prescription of replacement therapy (EPRT). Our aim was to identify factors influencing and explaining different prescription patterns across European countries. We conducted a retrospective, multicenter study using the Eurocrine database, focusing on patients undergoing HT for histologically-proven benign conditions. Analyzed variables included the country where surgery was performed, as well as epidemiological, clinical, surgical and pathological data. The dependent variable was EPRT, assessed 30-45 days after surgery. Associations between qualitative variables and the likelihood of receiving EPRT were tested using Chi-square or Fisher's exact tests. A multivariate logistic regression model was developed to identify independent predictors. 14,484 patients undergoing HT between 2015 and 2022 were included. Median age was 52 years, and 11,345 (78.3%) were female. The most common indication for surgery was excluding malignancy in 7873 cases (54.3%). Overall, 4653 patients (32.1%) received EPRT, with significant variability among countries, ranging from 3 to 95%. Independent risk factors for EPRT included female sex, older age, malignancy and thyrotoxicosis as surgical indications, Bethesda III cytology, thyroiditis on histology, and the country where HT was performed. One-third of European patients undergoing HT for confirmed benign conditions required EPRT. That prescription was more likely among older patients, those with suspected malignancy or thyrotoxicosis as surgical indications, suspicious cytology, and thyroiditis on histology. Additionally, the country where surgery was done played a significant role.