150 patients divided into two groups.The experimental group was submitted at the assay of iPTH six hours after surgery whilst the control group was submitted to a daily assay of serum calcium and phosphorus.

Purpose: The aim of this randomized controlled trial was to validate the results of a previous prospective cohort study conducted in the same surgical unit regarding the use of concomitant intact parathyroid hormone (iPTH) and serum calcium measurement in predicting hypocalcemia after total thyroidectomy.

Methods: From January 2014 to January 2015, 150 patients underwent total thyroidectomy in our department and were divided into two groups. The experimental group was submitted at the assay of iPTH six hours after surgery whilst the control group was submitted to a daily assay of serum calcium and phosphorus. Sensitivity and specificity of different serum measurements have been calculated using the Receiver-operator characteristics (ROC) curve.

Inclusion Criteria:

• Be submitted to total thyroidectomy during the study period
• Have signed the informed consent

Exclusion Criteria:

• Lack of inclusion criteria
• Lobectomy with isthmusectomy or partial or subtotal thyroidectomy
• Completion thyroidectomy
• Concomitant hyperparathyroidism was present
• Concomitant treatment with oral calcium and/or vitamin D prior to surgery