Hypocalcemia is a common complication following
thyroidectomy. However, the incidence of postoperative
hypocalcemia varies widely in the literature, and factors associated with
hypocalcemia after thyroid surgery are not well established. We aimed to identify incidence trends and independent risk factors of postoperative
hypocalcemia using the nationwide inpatient sample (NIS) database from 1998 to 2008. Overall, 6,605 (5.5%) of 119,567 patients who underwent
thyroidectomy developed
hypocalcemia. Total
thyroidectomy resulted in a significantly higher increased incidence (9.0%) of
hypocalcemia when compared with unilateral thyroid lobectomy (1.9%; P < .001).
Thyroidectomy with bilateral
neck dissection, the strongest independent risk factor of postoperative
hypocalcemia (odds ratio, 9.42; P < .001), resulted in an incidence of 23.4%. Patients aged 45 years to 84 years were less likely to have postoperative
hypocalcemia compared with their younger and older counterparts (P < .001). Hispanic (P = .003) and Asian (P = .027) patients were more likely, and black patients were less likely (P = .003) than white patients to develop
hypocalcemia. Additional factors independently associated with postoperative
hypocalcemia included female gender, nonteaching hospitals, and
malignant neoplasms of thyroid gland.
Hypocalcemia following
thyroidectomy resulted in 1.47 days of extended
hospital stay (3.33 versus 1.85 days P < .001).