*3.1. Data Extraction*

The process of article selection is illustrated in Figure 1. The database searches retrieved 695 articles, and a reference list search retrieved 15 additional studies. After deduplication, 590 articles were screened, of which 67 full articles were retrieved. A total of 25 studies met the inclusion criteria. Overall, the outcomes of nearly 3000 patients were described. All included studies were published between 2016 and 2021, and the mean ages of the included participants ranged from 39.2 to 61.6 years for 22 studies, while three studies did not report the ages of their participants. Two studies reported age ranges (32–70 and 34–73 years, respectively) [42,43]. Five studies were retrospective, and seven studies had a control group. Three studies exclusively evaluated patients with thyroid cancer, whereas the remaining studies assessed patients with thyroid cancer and other thyroid or parathyroid diseases. The study characteristics of the included studies are presented in Table 1.

**Table 1.** Study characteristics of included studies. \* Mean ± standard deviation unless otherwise stated.





**Figure 1.** Flow diagram of study selection.
