Figure 1.

Figure 2.

Figure 3.

Figure 4.

Combined data of side effects
| Chen | Ren | Zhang | Qin | Total | |
|---|---|---|---|---|---|
| Hoarseness | 2/14 | 6/47 | – | 9/32 | 17/93 (18.3%) |
| Hypercalcemia | 4/14 | 26/47 | – | – | 30/61 (49.2%) |
| RLN injury | – | – | 5/30 | 2/9 | 7/39 (17.9%) |
Quality assessment of cohort studies
| Reference | Is the case definition adequate? | Representativeness of the cases | Selection of controls | Definition of controls | Comparability of cases and controls on the basis of the design or analysis | Ascertainment of exposure | Same method of ascertainment for cases and controls | Nonresponse rate | Total scores |
|---|---|---|---|---|---|---|---|---|---|
| Chen et al., [36] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 8 |
| Ren et al., [37] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ☆ | 7 |
| Zhang et al., [38] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ☆ | 7 |
| Qin et al., [39] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 8 |
Basic information of the included studies
| Reference | Country | Institution | Design | Sample size | Gender (male/female) | Mean age (years) | Follow-up period (months) | Conducted period | Follow-up time point (d/months) | Complications (N) |
|---|---|---|---|---|---|---|---|---|---|---|
| Chen et al., [36] | Taiwan, China | The Kaohsiung Chang Gung Memorial Hospital Medical Center in Taiwan | Retrospective study | 9 | 6/3 | 51.80 ± 16.00 | 12 | 2019.04–2020.12 |
|
|
| Ren et al., [37] | China | Zhejiang Provincial People's Hospital | Retrospective study | 47 | 29/18 | 51 ± 12 | 28.6 (21.3–36.6) | 2014.06–2020.12 |
|
|
| Zhang et al., [38] | China | Fujian Provincial Hospital | Retrospective study | 30 | 16/14 | 45.8 ± 13.3 | 6 | 2018.01–2021.02 |
|
|
| Qin et al., [39] | China | Nanchong Central Hospital | Retrospective study | 32 | 13/19 | 53.53 ± 13.64 | 12 | 2018.11–2019.05 |
|
|
Publication bias analyses were performed using Egger's test
| Outcomes | Follow-up time point | t | P |
|---|---|---|---|
| Serum PTH | 1 d | −1.313 | 0.320 |
| 6 months | −0.819 | 0.499 | |
| 12 months | −0.849 | 0.552 | |
| Serum calcium | 1 d | −1.942 | 0.192 |
| 6 months | −0.577 | 0.622 | |
| Serum phosphorus | 1 d | −0.652 | 0.632 |
| 6 months | −0.219 | 0.863 |