Characteristics of 6 studies
| Authors | Year | Region | Period | Total No. | NOS |
|---|---|---|---|---|---|
| Tshering Vogel et al5 | 2013 | Switzerland | 2007–2010 | 46 | 4 |
| Razek et al7 | 2015 | Egypt | NR | 41 | 4 |
| Vaid et al11 | 2017 | India | 8 months | 80 | 4 |
| Becker et al10 | 2018 | Switzerland | NR | 74 | 4 |
| Jajodia et al13 | 2019 | India | 1 year | 62 | 4 |
| Huang et al14 | 2019 | China | 2016–2017 | 62 | 5 |
Note:—NR indicates not reported; NOS, Newcastle-Ottawa scale.