Study | Level 1 | Level 2a | Level 2b | Level 3 | Level 4a | Level 4b | Level 4c |
|---|
Schuster et al. [40] | – | 2 | 7 | 1 | – | – | – |
Cocks et al. [38] | 1 | 4 | 6 | 2 | | – | – |
Sevdalis et al. [41, 44] | 3 | 3 | 7 | 1 | – | – | – |
Rao et al. [37] | 2 | 2 | 4 | – | – | – | – |
Davison et al. [39] | 6 | 3 | 3 | | | | |
Anton et al. [36] | 5 | 7 | 11 | 4 | – | – | – |
