Hypoparathyroidism After Total Thyroidectomy: A Population-Based Analysis of California Databases

Postthyroidectomy hypoparathyroidism is common and usually managed as an outpatient. A better understanding of patients at risk for an emergency department (ED) visit can improve health-care utilization and patient care.

The California Cancer Registry and Health Care Access and Information Databases were linked to identify patients who underwent a thyroidectomy for thyroid cancer 2005-2018 and had an ED visit for hypoparathyroidism within 2 y of surgery. Cumulative incidence and multivariable Cox proportional hazards models were used to identify factors associated with an ED visit.

Among 41,502 thyroidectomy patients, 588 (1.42%) presented to the ED for hypoparathyroidism, with a median time between thyroidectomy and first ED visit of 4 ds. Two-year cumulative incidence was highest for women (1.56%), Hispanic patients (2.04%), younger adults aged 18-40 y (1.97%), higher Charlson comorbidity index score (2.43%), lowest neighborhood socioeconomic status quintile (1.97%), patients with >4 lymph nodes removed (2.04%), and patients not seen at an American College of Surgeons Committee on Cancer site (1.60%). Multivariable analysis revealed several factors associated with an increased risk of hypoparathyroidism, including female gender (hazard ratio [HR] 1.67, 95% confidence interval [CI] = 1.32-2.10), Hispanic ethnicity (HR 1.41, 95% CI = 1.16-1.71), a higher Charlson comorbidity index score (≥2 = HR 1.91 [95% CI = 1.46-2.51]), and patients with >4 lymph nodesremoved (HR 1.70 [95% CI = 1.43-2.01]).

ED visits for postthyroidectomy hypoparathyroidism are uncommon, but usually occurs shortly after surgery. Most risk factors identified are not modifiable, but they help identify high-risk patients who could benefit from targeted postoperative care (programs) to reduce unplanned ED visits.