To supplement or not to supplement: a cost-utility analysis of calcium and vitamin D repletion in patients after thyroidectomy.

Background: Postoperative hypocalcemia is the most common complication after thyroidectomy; prevention and treatment remain areas of ongoing debate. The purpose of this study was to determine the incremental cost utility of routine versus selective calcium and vitamin D supplementation after total or completion thyroidectomy.

Methods: A cost-utility analysis using a Markov decision model was performed for a hypothetical cohort of adult patients after thyroidectomy. Routine or selective supplementation of oral calcium carbonate, vitamin D (calcitriol), and intravenous calcium gluconate, when required, was used. Selective supplementation was determined by serum intact parathyroid hormone levels. The incremental cost utility, measured in U.S. dollars per quality-adjusted life-year (QALY), was calculated.

Results: In the base-case analysis, the cost of routine supplementation was $102 versus $164 for selective supplementation. Patients in the routine arm gained 0.002 QALYs compared to patients in the selective arm (0.95936 QALYs vs. 0.95725 QALYs). At the population level, this translates into a savings of $29,365/QALY (95% confidence interval, -$66,650 to -$1,772) for routine supplementation. Sensitivity analyses demonstrated that the model was most sensitive to the utility of the hypocalcemic state, postoperative rates of hypocalcemia, and cost of serum parathyroid hormone testing.

Conclusions: Routine oral calcium and calcitriol supplementation in patients after thyroidectomy seems to be less expensive and results in higher patient utility than selective supplementation. Surgeons who have very low rates of hypocalcemia in their patients may benefit less from routine supplementation.