Endocrine Abstracts

Background: Hypoparathyroidism, a rare endocrine disorder characterised by low serum calcium due to low or insufficient parathyroid hormone levels, most commonly occurs post-surgery although can also occur due to predisposing genetic conditions or idiopathically. Hypoparathyroidism requires long-term medical management to minimise complications and detrimental impacts on health-related quality of life. Few real-world studies, particularly in the UK, have quantified healthcare resource use (HCRU) associated with chronic hypoparathyroidism.

Aims: To describe demographic characteristics and HCRU associated with post-surgical and non-surgical chronic hypoparathyroidism, compared with matched controls without hypoparathyroidism, using a Clinical Practice Research Datalink (CPRD), Hospital Episode Statistics (HES), and Office of National Statistics deaths registrations linked dataset.

Methods: Primary care data from CPRD linked to HES and death registrations in England, were used to retrospectively identify two adult hypoparathyroidism cohorts. The first, incident chronic hypoparathyroidism induced by surgery or radiotherapy between 01/04/2008–22/03/2019, with a look-back to 01/04/2007 to identify prior surgery or radiotherapy. The second, prevalent chronic hypoparathyroidism that was not surgically induced between 01/04/2008–22/03/2020. Both cohorts were indexed upon diagnosis of chronic hypoparathyroidism, defined as having two diagnosis codes 6-36 months apart or ongoing calcium or vitamin D analogue prescription in lieu of a second diagnosis code. Both hypoparathyroidism cohorts were matched with controls on age and gender. We estimated all-cause inpatient admissions and bed days per person per year (PPPY) for individuals with chronic hypoparathyroidism and those without.

Results: 183 individuals with surgical and 447 with non-surgical chronic hypoparathyroidism were identified. Individuals in the post-surgical cohort were younger than those in the non-surgical (mean age: 53.3 vs 57.1 years) and a higher proportion were female (73.8% vs 62.7%). Over a median follow-up time of 56.5 months, individuals with post-surgical chronic hypoparathyroidism incurred more admissions (mean 14.1 PPPY vs 0.4 PPPY, mean difference 13.7, [11.9–15.5], P<0.001) and annual bed days (mean 7.9 PPPY vs 0.9 PPPY, mean difference 7, [5.4–8.8], P<0.001) compared to controls. The same trend was observed amongst individuals with chronic non-surgical hypoparathyroidism, who, over a median follow-up time of 44.9 months, had more admissions (4.5 PPPY vs 0.4 PPPY, mean difference 4.0, [2.9–5.6], P<0.001) and bed days (14.9 days PPPY vs 1.7 days PPPY, mean difference 13.2, [11.8-14.6], P<0.001) than controls.

Conclusion: Our results suggest that HCRU is significantly greater for individuals with chronic hypoparathyroidism compared to non-hypoparathyroidism controls, highlighting the need for effective treatment options in patients with chronic hypoparathyroidism.