Transient hypoparathyroidism (TH) is the main post-thyroidectomy complication, impacting surgical outcomes, hospitalization length and perceived quality. This study aims to identify possible associated risk factors.

We analyzed 238 thyroidectomies (2020-2022), excluding partial surgery, primary hyperparathyroidism, neck irradiation history and chronic kidney disease. Variables considered: demographics, histology, autoimmunity, thyroid function, pre- and postoperative Vitamin D levels (where available), type of surgery, number of incidentally removed parathyroids (IRP), and surgeon experience (>1000 thyroidectomies, <500, in training). Univariate analysis applied: χ², Fisher's exact test for categorical variables, and Student's T-test for continuous variables. Subsequently, logistic multivariate analysis with stepwise selection was performed.

Univariate analysis did not yield statistically significant results for the considered variables. However, "No Complications" group displayed a mean age of 55 years, whereas TH group showed a mean age of 51 (p-value=0.055). Subsequently, we built a multivariate logistic model. This model (AIC=245.02) indicated that the absence of incidental parathyroidectomy was associated with the age class >55 years, presenting an odds ratio (OR) of 9.015 (p-value <0.05). Simultaneously, the age class >55 years exhibited protective effects against TH, demonstrating an OR of 0.085 (p-value <0.01). Similarly, "no IRP" was found to be protective for TH, with an OR of 0.208 (p-value <0.01).

Multivariate analysis highlighted that having "no IRP" was protective for TH while younger age was a risk factor. Surgeon experience seemed unrelated to IRP or outcomes, suggesting that adequate tutoring and/or a case volume near 500 suffice for good results. Parathyroid reimplantation impact was not evident in transient hypoparathyroidism.