Opportunities to improve the diagnosis and treatment of primary hyperparathyroidism: retrospective cohort study.

BACKGROUND

Although primary hyperparathyroidism (PHPT) is readily diagnosed biochemically and can be cured with low-risk surgery, it is often underrecognized and undertreated. Our objectives were to characterize, within our health system, how often patients with hypercalcemia were evaluated for PHPT and how often patients with PHPT underwent definitive treatment with parathyroidectomy.

METHODS

Ambulatory patients aged 18 years or older seen at our health system between January 2018 and June 2023 with chronic hypercalcemia were identified from the medical record. After excluding causes of secondary hyperparathyroidism, the proportion of patients with parathyroid hormone (PTH) tests was calculated. Among patients with biochemical evidence of PHPT, the proportion of patients who underwent parathyroidectomy was calculated. Multivariable logistic regression was used to identify factors associated with an evaluation for PHPT and, separately, with parathyroidectomy.

RESULTS

Of 7,675 patients with chronic hypercalcemia, 3,323 (43.3%) had a PTH test obtained within 6 months. An age between 40-49 <30 years [(odds ratio (OR) =3.2; 95% confidence interval (CI): 1.8-5.6; P<0.001], a serum calcium level between 11.6-12.0 <11.0 mg/dL (OR =3.9; 95% CI: 3.2-4.7; P<0.001), and osteoporosis (OR =3.1; 95% CI: 2.7-3.5; P<0.001) were associated with an evaluation for PHPT. Among those with PTH levels, 1,327 (39.9%) had PHPT but only 916 (69.0%) were recognized. Three hundred and forty-five (26.0%) patients with PHPT underwent parathyroidectomy. An increasing number of surgical indications was associated with parathyroidectomy (P<0.001), though overall rates remained less than 40%. Among indications for surgery, including age and serum total calcium level, only osteoporosis was associated with parathyroidectomy (OR =2.0; 95% CI: 1.4-2.8; P<0.001).

CONCLUSIONS

In this study, more than half of patients with chronic hypercalcemia were not evaluated for PHPT. Among patients with biochemical evidence of PHPT, one-third were unrecognized and only one-in-four received curative treatment. Opportunities to improve the management of PHPT exist within our large integrated health system.