| Safety policy (A) | Kwon et al. (2021), Lyu et al. (2018), Rotimi et al. (2021) |
| Safety training (B) | Hussain et al. (2020), Ibarra-Mejía et al. (2021), Vignoli et al. (2021) |
| Communication barriers (C) | Ibarra-Mejía et al. (2021), Lyu et al. (2020), Pink et al. (2010) |
| Cultural differences (D) | Al-Bayati et al. (2018), Hare et al. (2013), Kim et al. (2015) |
| Personal variables (E) | Ibarra-Mejía et al. (2021), Lyu et al. (2018), Welton et al. (2018) |
| Safety outcomes (O) | Lyu et al. (2018), Ghodrati et al. (2018), Newaz et al. (2023) |