TABLE 1.
Summary of the studies by countries.
| Countries in which studies were conducted | Number of studies | References |
|---|---|---|
| China | 7 | Cheng et al., 2016; Sun, 2014; Tang et al., 2013; Wang et al., 2019; Xue et al., 2018; Yang et al., 2019; Yu et al., 2016 |
| South Korea | 5 | Jeong et al., 2020; Han et al., 2014; Kim et al., 2009; Kim et al., 2018; Yoon et al., 2018 |
| Singapore | 4 | Netto et al., 2009; Vaingankar et al., 2016; Tay et al., 2016; Yuan et al., 2023 |
| Thailand | 3 | Ondee et al., 2013; Pankong et al., 2018; Pothiban et al., 2020 |
| Taiwan | 3 | Bai et al., 2024; Huang et al., 2006; Su & Chang, 2020 |
| Turkey | 1 | Ar & Karanci, 2019 |
| Pakistan | 1 | Ali & Bokharey, 2015 |
| Iran | 1 | Saffari et al., 2018 |
| Saudi Arabia | 1 | Khusaifan & El Keshky, 2017 |
| India | 1 | Pandya, 2019 |