Table 1.
Characteristics of the included studies in the meta-analysis.
| No. | First author | Publication year | Study period(year/month) | Location | Sample size (n) | PTC patients | Non-PTC individuals | Urine samples | Measurement of UIC | Score |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Wang (22) | 2014 | 2010/06-2011/06 | China | 460 | 103 PTC patients | 306 healthy individuals; 51 BTN patients | Morning urine | As-Ce catalytic spectrophotometry | 8 |
| 2 | Kim (23) | 2017 | 2010/11-2015/03 | Korea | 215 | 215 PTC patients | – | Fasting, spot-urine | ICP-MS | 8 |
| 3 | Zhao (24) | 2018 | 2013/11-2015/03 | China | 2041 | 1120 PTC patients | 921 NG patients | Spot urine | As-Ce catalytic spectrophotometry | 7 |
| 4 | Celik (25) | 2020 | 2015-2018 | Turkey | 132 | 88 PTC patients | 44 BTN patients | Spot urine in the morning | As-Ce catalytic spectrophotometry | 6 |
| 5 | Hou (26) | 2020 | 2017/01-2019/03 | China | 488 | 214 PTC patients | 82 healthy individuals; 192 BTT patients | Random spot urine | As-Ce catalytic spectrophotometry | 9 |
| 6 | Huang (27) | 2020 | 2019/07-2019/12 | China | 151 | 97 PTC patients | 54 BTN patients | Fasting urine in the morning | As-Ce catalytic spectrophotometry | 7 |
| 7 | Fan (28) | 2021 | 2015/03-2018/03 | China | 402 | 402 PTC patients | – | Urine after fasting and avoiding alcohol and medicine for 12 h | As-Ce catalytic spectrophotometry | 7 |
| 8 | Kim (29) | 2021 | 2010/04-2014/12 | Korea | 946 | 446 PTC patients | 500 healthy individuals; | Urine after an 8-hour fast | ICP-MS | 9 |
| 9 | Yu (30) | 2021 | 2016/01-2020/12 | China | 1341 | 285 PTC | 874 healthy individuals; 745 other thyroid diseases | Random spot urine | As-Ce catalytic spectrophotometry | 8 |
| 10 | Wang (31) | 2022 | 2018/09-2019/09 | China | 368 | 112 PTC patients | 184 healthy individuals; 72 BTN patients |
Morning fasting middle-segment urine | ICP-MS | 7 |