Defining the Characteristics of Chronic Hypoparathyroidism Not Adequately Controlled on Conventional Therapy: Consensus Findings of Three European Delphi Panels

INTRODUCTION: European Society of Endocrinology (ESE) guidelines provide goals for hypoparathyroidism management but do not define characteristics of chronic hypoparathyroidism that is not adequately controlled. Three European country-specific Delphi panels were conducted to gain consensus on these characteristics. METHODS: Delphi panels were conducted in the UK, Sweden, and Portugal using similar methodology. At each round, panellists considered patients with chronic hypoparathyroidism whose disease is not adequately controlled on conventional therapy according to a matrix of four presentations of patients with chronic hypoparathyroidism: normal biochemical levels/well (group 1), abnormal biochemical levels/well (group 2), normal biochemical levels/unwell (group 3), and abnormal biochemical levels/unwell (group 4), with wellness defined by the patient's persistent symptoms, comorbidities, and complications. For groups 2-4, panellists rated characteristics in five categories (patient characteristics, family history, comorbidities, biochemistry, and symptoms/impact on quality of life QoL) with respect to defining a patient as having chronic hypoparathyroidism that was not adequately controlled on conventional therapy. Consensus was achieved when more than 80% of respondents agreed. RESULTS: Among the three countries, panellists agreed that characteristics within four of the five categories (patient characteristics, comorbidities, biochemistry, and symptoms/impact on QoL) were important for defining inadequate control. Characteristics deemed important in groups 2-4 included a history of compliance problems and chronic kidney disease stages 4 and 5. In groups 2 and 4, the biochemical parameters deemed important were serum calcium, urinary calcium, and serum creatinine. In groups 3 and 4, tingling or numbness in the hands/feet and face was the only symptom deemed important in all three countries. CONCLUSION: Delphi panels conducted in three European countries provided national consensus on key parameters of patient characteristics, biochemistry, comorbidities, and symptoms/impact on QoL that define not adequately controlled chronic hypoparathyroidism. These characteristics should be tested more widely for their applicability in clinical practice. FUNDING: Shire International GmbH, Zug, Switzerland, a member of the Takeda group of companies.