Factors predicting post-thyroidectomy hypoparathyroidism recovery.

BACKGROUND: Hypoparathyroidism is the most common complication after thyroidectomy and the main reason for frequent outpatient visits; however, there is a poor understanding of its outcomes and no clear follow-up strategies are available. We aimed to predict post-thyroidectomy hypoparathyroidism outcomes and identify relevant factors.
METHODS: A multicenter, standardized prospective study was conducted. The parathyroid hormone level (PTH) was measured preoperatively and at the first hour after surgery, then at each outpatient follow-up visit after 1 week, 3 weeks, and 1 month, and then every 2 months, until it either reached normal values or up to 6 months. Cox proportional hazard modeling was used to determine the factors that affect PTH recovery. A Weibull distribution model was used to predict time to recovery. Both models were evaluated by goodness of fit.
RESULTS: A total of 186 patients were enrolled in the study; 53 (28.5 %) developed hypoparathyroidism, 47 of them (88.6 %) females. Their mean age was 41.2 years, and 11.4 % were diabetic. Of these women, 33 (62.3 %) recovered within 1 month, 10 (18.9 %) recovered after 1 month but within 6 months, 7 (13.2 %) did not recover within 6 months, and 3 (5.6 %) missed follow-up. Factors that are found to affect and predict the speed of recovery were the preoperative PTH level, perioperative percent drop in PTH level, diabetes mellitus, and gender.
CONCLUSIONS: This study provides potentially useful information for early prediction of PTH recovery, and it highlights the factors that affect the course of hypoparathyroidism recovery, which in turn should be reflected in better patient management, improved patient satisfaction, and overall cost-effectiveness.