Persistent Postthyroidectomy Hypoparathyroidism in the Netherlands

Importance: Hypoparathyroidism is one of the most common complications after total or completion thyroidectomy. The reported incidence rate of hypoparathyroidism in the literature is highly variable. Data that provide a better understanding of the magnitude of this postoperative complication are warranted and can provide a stepping stone for further collaborations that aim to reduce complication rates and establish uniform treatment protocols. Objective: To evaluate the incidence of postoperative, persistent hypoparathyroidism after total or completion thyroidectomy in patients who were referred to university hospital centers and assess the association of different definitions with the incidence of hypoparathyroidism. Design, Setting, and Participants: This retrospective multicenter cohort study conducted throughout 2016 in 7 Dutch university hospital centers included 200 patients who were undergoing a total or completion thyroidectomy. Data analysis was conducted in January 2021. Main Outcomes and Measures: We report on the incidence of persistent hypoparathyroidism, defined as the need for active vitamin D with or without calcium supplementation longer than 1 year after surgery. Results: A total of 200 patients (143 women [71.5%]; mean [IQR] age, 49.0 [37.0-62.0] years) were included and 30 patients (15.0%) developed persistent hypoparathyroidism. The incidence of persistent hypoparathyroidism varied between 14.5% (calcium and active vitamin D 1 year postsurgery) to 28.5% (calcium and/or active vitamin D 6 months postsurgery) depending on the definition used. Conclusions and Relevance: In this cohort study, the risk of persistent hypoparathyroidism after total or completion thyroidectomy was 15% in patients who were referred to university hospital centers. The high rate of persistent hypoparathyroidism warrants efforts to reduce this complication rate. There is discrepancy in the definition and treatment of persistent hypoparathyroidism, and use of uniform evidence-based treatment guidelines enables comparison of interventions..