Analysis of Time to Diagnosis and Outcomes Among Adults With Primary Hyperparathyroidism

IMPORTANCE: Despite access to routine laboratory evaluation, primary hyperparathyroidism (PHP) remains underdiagnosed and undertreated. OBJECTIVE: To determine the consequences associated with missed diagnoses and prolonged time to diagnosis and treatment of PHP. DESIGN, SETTING, AND PARTICIPANTS: This is a retrospective cohort study of patients older than 40 years with 2 instances of hypercalcemia during 2010 to 2020 and 3 years of follow-up. Patients were recruited from 63 health care organizations in the TriNetX Research Network. Data analysis was performed from January 2010 to September 2020. EXPOSURES: Elevated serum calcium. MAIN OUTCOMES AND MEASURES: Existing symptoms and diagnoses associated with PHP (osteoporosis, fractures, urolithiasis, major depressive disorder, anxiety, hypertension, gastroesophageal reflux disease, malaise or fatigue, joint pain or myalgias, constipation, insomnia, polyuria, weakness, abdominal pain, headache, nausea, amnesia, and gallstones) compared in patients deemed high-risk and without a diagnosis and matched controls, and those who experienced times from documented hypercalcemia to diagnosis and diagnosis to treatment within or beyond 1 year. RESULTS: There were 135 034 patients analyzed (96 554 women [72%]; 28 892 Black patients [21%] and 88 010 White patients [65%]; 3608 Hispanic patients [3%] and 98 279 non-Hispanic patients [73%]; mean [SD] age, 63 [10] years). Two groups without a documented diagnosis of PHP were identified as high risk: 20 176 patients (14.9%) with parathyroid hormone greater than or equal to 50 pg/mL and 24 905 patients (18.4%) with no parathyroid hormone level obtained or recorded explanation for hypercalcemia. High-risk patients experienced significantly increased rates of all associated symptoms and diagnoses compared with matched controls. Just 9.7% of those with hypercalcemia (13 136 patients) had a diagnosis of PHP. Compared with individuals who received a diagnosis within 1 year of hypercalcemia, those whose workup exceeded 1 year had significantly increased rates of major depressive disorder, anxiety, hypertension, gastroesophageal reflux disease, malaise or fatigue, joint pain or myalgias, polyuria, weakness, abdominal pain, and headache at 3 years. The rate of osteoporosis increased from 17.1% (628 patients) to 25.4% (935 patients) over the study period in the group with delayed diagnosis. Among those with a diagnosis, 5280 patients (40.2%) underwent parathyroidectomy. Surgery beyond 1 year of diagnosis was associated with significantly increased rates of osteoporosis and hypertension at 3 years after diagnosis compared with those treated within 1 year. CONCLUSIONS AND RELEVANCE: Many patients were at high risk for PHP without a documented diagnosis. Complications in these patients, as well as those who received a diagnosis after prolonged workup or time to treatment, resulted in patient harm. System-level interventions are necessary to ensure proper diagnosis and prompt treatment of PHP.