Table 1. Baseline characteristics of patients and study design in the included studies.
| First author | Year | Sample size | Median age [range] year | Sex (male/female) | Patient source | Research design |
|---|---|---|---|---|---|---|
| Yi-Chao Wang | 2015 | 442 | ET: 36.1±9.7; COT: 40.8±9.0 | ET: 13/211; COT: 20/198 | West China Hospital of Sichuan University | Prospective randomized controlled trial |
| Rui Qu | 2018 | 76 | ET: 6.7±10.0; COT: 43.2±14.3 | ET: 9/31; COT: 14/22 | First Affiliated Hospital of Jinan University | Prospective randomized controlled trial |
| Yoon Woo Koh | 2009 | 59 | ET: 36.5±5.1; COT: 38.3±4.5 | ET: 3/26; COT: 6/24 | Soonchunhyang University College of Medicine | Prospective randomized controlled trial |
| Ki Nam Park | 2015 | 152 | ET: 38.0±9.4; COT: 50.8±11.5 | ET: 4/46; COT: 14/88 | SoonChunHyang University College of Medicine | Prospective randomized controlled trial |
| Hayemin Lee | 2012 | 78 | ET: 42.3±7.6; COT: 49.0±10.8 | ET: 0/37; COT: 3/38 | Bucheon St. Mary’s Hospital, The Catholic University of Korea | Prospective randomized controlled trial |
| Doh Young Lee | 2015 | 280 | ET: 25.9±7.4; COT: 24.9±7.3 | ET: 12/64; COT: 37/167 | Korea University College of Medicine | Prospective randomized controlled trial |
| Seon Kwang Kim | 2015 | 1,003 | ET: 38.9 [17–57]; COT: 49.53 [17–84] | ET: 13/173; COT: 96/830 | Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital | Retrospective review |
| Eun Young Kim | 2017 | 738 | ET: 39.5±0.8; COT: 48.9±0.5 | ET: 8/192; COT: 138/400 | Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine | Retrospective review |
| Jong Ju Jeong | 2009 | 499 | ET: 39.6±8.8; COT: 49.5±10.2 | ET: 7/268; COT: 35/189 | Yonsei University College of Medicine | Retrospective review |
| Kyung Tae | 2011 | 88 | ET: 36.2±9.9; COT: 44.6±11.8 | ET: 1/30; COT: 11/25 | College of Medicine, Hanyang Universitye | Retrospective review |
| Weili Gao | 2013 | 67 | ET: 38.94±11.58; COT: 40.79±11.14 | ET: 8/27; COT: 7/26 | Huzhou Central Hospital, Zhejiang | Retrospective review |
ET, endoscopic thyroidectomy; COT, conventional open thyroidectomy.