J. O’Connor1, R. Sippel2, A. Kind3,4, A. Chiu2 1University Of Wisconsin, School Of Medicine And Public Health, Madison, WI, USA 2University Of Wisconsin, Section Of Endocrine Surgery, Department Of Surgery, Madison, WI, USA 3University Of Wisconsin, Center For Health Disparities Research, Madison, WI, USA 4University Of Wisconsin, Department Of Medicine, Madison, WI, USA
Introduction: Primary hyperparathyroidism (PHPT) affects approximately 1% of adults in the United States. Untreated PHPT is associated with osteopenia/osteoporosis, nephrolithiasis, and increased risk of cardiovascular events. Currently, the only curative therapy for PHPT is surgical parathyroidectomy. Although the procedure is safe, successful, and cost-effective, it remains underutilized, particularly among historically disadvantaged populations. We sought to better understand the association social determinants, as measured by neighborhood advantage, have on the workup of hypercalcemia and referral to specialists for management of PHPT.
Methods: We performed a retrospective analysis of all patients ≥ 18 years of age with an elevated calcium value (>10.2 mg/dl) and established with a primary care provider in our academic healthcare system between January 1, 2021 and January 1, 2023. Patient demographic (age, gender, race, nine digit zip-code, and insurance status) and laboratory information (initial high calcium value, five subsequent calcium levels, and PTH) were abstracted. Exclusion criteria included patients with Stage 4 or 5 kidney failure, secondary or tertiary HPT, history of kidney transplant, or prior parathyroidectomy. Patients were grouped into likely (>65pg/mL), possible (30-65 pg/mL), or unlikely (<30 pg/mL) PHPT based on PTH lab values. Patients’ neighborhood advantage was stratified using the Area Deprivation Index (ADI), a composite measure of community factors such as income, education, employment, and housing quality, to create three cohorts — disadvantaged, moderate, advantaged. The primary outcome was specialist referral for PHPT management. Multivariate logistic regression was performed to evaluate factors associated with specialist referrals.
Results: A total of 6,562 patient with hypercalcemia were identified and 3,543 (54.0%) met inclusion criteria. The study cohort was 91.4% White, 60.2% female, 84.7% privately insured, and 54.5% under 65 years of age. PTH levels were checked for only 959 (27.1%) patients, of which 530 (55.3%) were determined to likely have PHPT. There were no significant differences for the rate of PTH workup (p = 0.26) or likely PHPT by neighborhood advantage (p = 0.70). However, patients in disadvantaged communities were significantly less likely to receive specialist referral compared to those living in advantaged communities (OR 0.72, CI 0.52 – 0.98). This was especially true for patients in disadvantaged neighborhoods who were deemed to have likely PHPT (OR 0.49 vs. advantaged, CI 0.26 – 0.92).
Conclusion: Overall, significant specialist referral disparities exist for PHPT management based on patient neighborhood advantage. 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.