Standardizing the reporting of postoperative hypoparathyroidism following thyroidectomy: consensus statement from the European Society of Endocrine Surgeons, the American Association of Endocrine Surgeons, and the International Association of Endocrine Surgeons

Postoperative hypoparathyroidism remains the most frequent complication following thyroid surgery, with reported incidence rates ranging from 14% to 60%1–7. While the majority of cases are transient and resolve within weeks, a substantial proportion (up to 25%) progress to persistent hypoparathyroidism, defined by sustained reductions in parathyroid hormone (PTH) and serum calcium levels beyond 6–12 months after surgery1,2,4,5. Despite its prevalence and clinical impact, postoperative hypoparathyroidism continues to be variably defined across studies and institutions. Terminology such as ‘postoperative parathyroid failure’, ‘protracted hypoparathyroidism’, and ‘permanent hypoparathyroidism’ has been proposed to reflect the temporal evolution of the condition6,7. However, the lack of standardized definitions and reporting criteria has hindered meaningful comparisons across clinical studies and limited the development of consistent management strategies7. Current approaches to hypoparathyroidism management range from short-term calcium and activated vitamin D supplementation to long-term replacement therapy and monitoring protocols7. These variations underscore the need for a unified framework to guide diagnosis, classification, and treatment. In addition to harmonizing definitions, there is a critical need to identify and standardize core variables that should be reported in surgical research related to hypoparathyroidism. These include biochemical parameters (for example PTH and calcium levels), timing of measurements, patient symptoms, and therapeutic interventions. Consistent reporting of these variables is essential to improve data comparability, facilitate meta-analyses, and guide evidence-based practice. Furthermore, hypoparathyroidism has emerged as a key quality marker in thyroid surgery. Its incidence and severity reflect not only surgical technique and intraoperative decision-making but also perioperative care and long-term follow-up. Establishing robust metrics for hypoparathyroidism, such as rates of transient versus permanent hypoparathyroidism, time to recovery, and need for chronic supplementation, can serve as benchmarks for surgical performance and institutional outcomes. In response to this gap, the European Society of Endocrine Surgeons (ESES), the American Association of Endocrine Surgeons (AAES), and the International Association of Endocrine Surgeons (IAES) collaborated to develop a consensus statement using a structured Delphi methodology. This initiative aims to standardize the reporting of hypoparathyroidism in clinical research and publications (including definitions, core variables to be reported, and quality markers and metrics of thyroid surgery related to hypoparathyroidism) and provide a globally accepted reference for clinicians and researchers in endocrine surgery. In November 2023, the ESES launched a collaborative initiative aimed at establishing a consensus on how hypoparathyroidism following thyroid surgery should be reported in the scientific literature. As part of this effort, the ESES formally reached out to the leadership of the AAES and the IAES, proposing the formation of a joint taskforce to address this important and timely issue. The proposal was met with unanimous support and all three societies appointed expert representatives in surgical thyroid disease to participate in the working group. Ultimately, the taskforce comprised 11 endocrine surgeons: 5 from the ESES (M.B., K.V.D.H., K.L., R.M., and M.R.), 3 from the AAES (K.N.P., R.S.S., and C.C.S.), and 3 from the IAES (J.C.L., O.N., and T.S.W.). This joint effort reflects a shared commitment across international societies to improve consistency and clarity in scientific reporting on hypoparathyroidism. The working group was convened to conduct a comprehensive and current review of the literature, develop the initial draft, and formulate relevant consensus statements. This process was carried out through a series of web-based meetings, complemented by ongoing electronic correspondence to ensure continuity and collaboration. A formal systematic review was deemed impractical and conceptually limiting for the purposes of this consensus statement. The primary challenge lay in the lack of a universally accepted definition of hypoparathyroidism and ‘surgical core variables’ relevant for prevalence of hypoparathyroidism that should be reported in scientific papers. As a result, it would have led to the exclusion of numerous pertinent studies. Conversely, many publications reference hypoparathyroidism without specifying the criteria applied, further complicating the selection process. To address this, targeted literature searches were conducted by dedicated subgroups of three members assigned to each thematic section. The remaining members of the working group were invited to critically appraise the findings and contribute additional high-quality references where appropriate. In areas where published evidence was lacking, expert opinion served as the basis for several statements. The initial draft and proposed statements were subsequently circulated among all working group members for review and refinement, before initiating the modified Delphi process. The modified Delphi method is a well-established process used to achieve consensus systematically and has recently been applied in several publications on thyroid cancer8,9. To reflect the diversity of clinical practice worldwide, while maintaining high expertise among contributing voters, the working group invited members of the ESES, the AAES, and the IAES, selected independently by each of the societies as experts in the field, to participate in a two-round modified Delphi process. The latter, along with the working group members, formed a panel of 92 panellists (full list in the Acknowledgements section) who voted on a dedicated invite-only electronic interface, powered by SurveyMonkey Inc. (San Mateo, CA, USA), thus providing coded data for analysis. Panellists voted on their level of agreement according to a Likert scale ranging from one (strongly disagree) to nine (strongly agree). The survey also allowed panellists to provide feedback and free-text comments on the statements during the first phase. Panellists with missing answers or with difficulties interpreting the statements were contacted individually through subsequent mailings for clarification. Appropriate revisions of the initial statements were made by the methodology leadership (M.B. and K.V.D.H.) supported by input from all taskforce experts according to the first survey feedback. The statements were considered to meet consensus if there was a mean score of ≥7.0 (agree) and either ≤9 (10%) outlier responses or ≤14 (15%) outlier responses with <7 responses scoring <5 (disagreement). Near-consensus was assigned to statements with a mean of ≥6.50 and ≤18 (20%) negative outliers. Non-consensus was the default if the above conditions were not met. Outliers were defined by any value at least two Likert points away from the mean. Negative outliers refer to outliers where the response was that of disagreement (<5). The quality of evidence for each statement was stratified as high, moderate, low, or expert opinion, depending on the type of publication that data were extracted from. Data stemming from RCTs were considered to represent high-quality evidence, whereas those from non-randomized prospective trials were of moderate quality and data from retrospective analyses or case series were deemed to be of low quality. Where no supportive data were available, the term expert opinion was used. 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