Who Gets Referred? Disparities in Access to Specialist Care for Hyperparathyroidism

Primary hyperparathyroidism (PHPT) is associated with significant patient morbidity, including increased risk of fractures, nephrolithiasis, and cardiovascular events. Parathyroidectomy remains an underutilized therapy, particularly among historically disadvantaged populations. We sought to better understand the association social determinants, as measured by neighborhood advantage, have on particular steps of the diagnostic and treatment pathway for PHPT to better identify targets for intervention.

We performed a retrospective analysis of all patients ≥18 y of age with an elevated calcium value (>10.2 mg/dL), and without a prior diagnosis of PHPT, secondary or tertiary hyperparathyroidism, or kidney failure, between January 1, 2021 and January 1, 2023. Patients' neighborhood advantage was stratified using the Area Deprivation Index to create three cohorts-disadvantaged, moderate, advantaged. The rates of repeat calcium check, parathyroid hormone (PTH) evaluation, specialist referral, and parathyroidectomy were compared.

A total of 6749 patients with hypercalcemia were identified, and 3976 (58.9%) met inclusion criteria. Repeat calcium was checked for 3646 (91.7%) of patients, and PTH checked in only 872 patients (57.5% of patients with repeat hypercalcemia). There was no difference in repeat calcium (P = 0.53) or PTH evaluation (P = 0.18) by neighborhood advantage. Significant differences were noted in rate of specialist evaluation (74.9% advantaged, 66.3% moderate, 59.8% disadvantaged, P < 0.01).

Referral to specialist is the step that contributed most to disparities in treatment rates of PHPT. Interventions addressing both individual- and community-level barriers, particularly in the transition of care from primary care to specialists, are needed to increase access to parathyroidectomy and further health equity.