Declining Rates of Inpatient Parathyroidectomy for Primary Hyperparathyroidism in the US

Parathyroidectomy is the only curative therapy for patients with primary hyperparathyroidism. However, the incidence, correlates and consequences of parathyroidectomy for primary hyperparathyroidism across the entire US population are unknown. We evaluated temporal trends in rates of inpatient parathyroidectomy for primary hyperparathyroidism, and associated in-hospital mortality, length of stay, and costs. We used the Healthcare Cost and Utilization Project Nationwide Inpatient Sample (NIS) from 2002-2011. Parathyroidectomies for primary hyperparathyroidism were identified using International Classification of Diseases, Ninth Revision codes. Unadjusted and age- and sex- adjusted rates of inpatient parathyroidectomy for primary hyperparathyroidism were derived from the NIS and the annual US Census. We estimated 109,583 parathyroidectomies for primary hyperparathyroidism between 2002 and 2011. More than half (55.4%) of patients were younger than age 65, and more than three-quarters (76.8%) were female. The overall rate of inpatient parathyroidectomy was 32.3 cases per million person-years. The adjusted rate decreased from 2004 (48.3 cases/million person-years) to 2007 (31.7 cases/million person-years) and was sustained thereafter. Although inpatient parathyroidectomy rates declined over time across all geographic regions, a steeper decline was observed in the South compared to other regions. Overall in-hospital mortality rates were 0.08%: 0.02% in patients younger than 65 years and 0.14% in patients 65 years and older. Inpatient parathyroidectomy rates for primary hyperparathyroidism have declined in recent years.