Seasonal Difference in Postthyroidectomy Hypocalcemia: A Montreal-Based Study

ObjectiveHypocalcemia following thyroidectomy often prolongs hospital stay and is potentially life-threatening. The objective of this study is to determine whether the season when thyroidectomy is performed is associated with postoperative hypocalcemia.Study DesignRetrospective case series of patients undergoing thyroid surgery from 2009 to 2015.SettingTertiary care academic institution in Montreal, Canada.Subjects and MethodsA consecutive sample of 823 patients undergoing thyroidectomy by a single high-volume otolaryngologist for a suspected or confirmed thyroid malignancy. Patient demographics, procedure type, calcium and vitamin D supplementation, and seasonal rate of hypocalcemia postthyroidectomy were calculated and compared.ResultsAverage seasonal rates of postthyroidectomy hypocalcemia in the winter, spring, summer, and autumn were, respectively, 8.3% (8 of 216), 7.3% (12 of 165), 1.5% (3 of 201), and 3.5% (8 of 228; P < .005). Patients operated in the winter were 5.6 times more likely to develop h...