Screening for primary hyperparathyroidism in a tertiary stone clinic, a useful endeavor.

Introduction And Objectives: Primary hyperparathyroidism (1HPT) is associated with the risk of developing kidney stones. Our objective was to determine the prevalence of 1HPT amongst SF evaluated at a tertiary stone clinic and determine if it is cost-effective to screen for this condition.

Methods: We retrospectively reviewed 742 adult SF seen by a single urologic surgeon from 2012 to 2017 all of who were screened for 1HPT with an intact serum PTH (iPTH) and calcium. The diagnosis of 1HPT was based on the presence of hypercalcemia with an inappropriately elevated iPTH or a high normal serum calcium and an inappropriately elevated iPTH. The diagnosis was confirmed by surgical neck exploration. Published cost data and stone recurrence rates were utilized to create a cost-effectiveness decision tree.

Results Obtained: Fifty-three (7.1%) were diagnosed with 1HPT. 15 (28%) had hypercalcemia and inappropriately elevated iPTH, 38 (72%) had high normal serum calcium levels and inappropriately elevated iPTH. The potential diagnosis was ignored/missed by primary care physicians in 9 (17.0%) based on a review of prior lab results. Cost modeling was undertaken for 5, 10, 15, and 20-year intervals after screening. Based on our prevalence data, historical risks for recurrence and published cost data for stone treatments, cost savings in screening are realized at 10 years.

Conclusion: These results support screening for primary hyperparathyroidism in patients evaluated in a tertiary referral setting.