Endocrine Abstracts

Hypoparathyroidism is a rare disorder characterised by hypocalcaemia and hyperphosphataemia in the presence of low or inappropriately normal parathyroid hormone levels. Currently there are limited data on the burden of illness and healthcare resource utilisation (HCRU) associated with chronic hypoparathyroidism in Canada. A retrospective cohort analysis with matched controls was conducted to examine HCRU in patients with chronic hypoparathyroidism in Ontario, Canada. Data were extracted from the ICES database, which includes 7 integrated sources of clinical information. Patient selection included the following 3 stepwise criteria for hypoparathyroidism: (1) Hypoparathyroidism diagnosis based on 5 hypoparathyroidism diagnosis codes, (2) inferred hypoparathyroidism based on ≥1 procedure associated with the development of hypoparathyroidism in combination with a Ca²⁺ metabolism disorder, and (3) inferred hypoparathyroidism in the presence of disorders associated with hypoparathyroidism in combination with a Ca²⁺ metabolism disorderaccompanied by a diagnosis of hypoparathyroidism or a recognised complication of hypoparathyroidism in the following 6–24 months. Patients’ baseline characteristics were assessed during a 1-year preindex period and were followed for up to 5 years after their index date, which was the date of the first diagnosis. Each patient was matched with 4 nonhypoparathyroidism controls based on age, sex, the Charlson Comorbidity Index, and hospitalisation (within ± 30 days of index date), and HCRU was compared using the Fisher exact test. The analysis included 427 patients with chronic hypoparathyroidism (mean age, 61 years; 75% female). Over the 5-year follow-up period, HCRU was significantly higher in patients with chronic hypoparathyroidism compared with the control cohort (Table). HCRU included visits to family physician/specialist, emergency department visits, same-day surgery, and hospitalisations. Patients with hypoparathyroidism had approximately 3-times-longer hospital stays during the first year of follow-up and overall longer hospital stays during all 5 years than the control group. Given the lack of a specific diagnostic code for hypocalcaemia, a code for both hypo- and hypercalcaemic diagnoses was used with selection criteria aimed at identifying those with hypoparathyroidism. Also, there was a time lag between data collection and data analyses. This study confirms the demographic features of patients with chronic hypoparathyroidism in Canada are consistent with other countries. Chronic hypoparathyroidism is associated with a substantial healthcare burden in patients and also on the healthcare system.

Funding: Shire, a Takeda company.