Table 5: Factor analysis.
| Paper | Factor analysis | Eigen value |
| Moerman, et al. 1996 [10] | Anxiety | 3.07 |
| Need for information | 1.25 | |
| Mohd Fahmi, et al. 2015 [17] | Anxiety | 4.1 |
| Need for information | 1 | |
| Nishimori, et al. 2002 [14] | Anxiety | 2.92 |
| Need for information | 1.30 | |
| Buonanno, et al. 2017 [18] | Anxiety | 3.41 |
| Need for information | 1.15 | |
| Berth, et al. 2007 [20] | Anxiety | > 1 |
| Need for information | > 1 | |
| Maurice-Szamburski, et al. 2013 [12] | Anxiety about anaesthesia | Not determined |
| Anxiety about surgery | Not determined | |
| Need for information | Not determined |