TABLE 2.
Risk of bias assessment.
| Studies | Random sequence generation | Allocation concealment | Selective reporting | Other sources of bias | Blinding (participants and personnel) | Blinding (outcome assessment) | Incomplete outcome data | *General risk of bias |
| Freese et al. (52) | L | L | H | L | L | U | L | L |
| Maron et al. (74) | L | L | L | L | L | U | L | L |
| Kovacs et al. (36) | L | L | H | L | U | U | L | L |
| Fukino et al. (59) | U | U | H | H | U | U | L | U |
| Westerterp-Plantenga et al. (51) (A) | U | U | H | H | L | U | H | U |
| Westerterp-Plantenga et al. (51) (B) | U | U | H | H | L | U | H | U |
| Chan et al. (75) | L | U | H | L | U | U | L | L |
| Diepvens et al. (33) | U | U | H | L | L | U | L | U |
| Hill et al. (35) | U | L | H | L | U | U | L | U |
| Nagao et al. (40) | L | L | H | L | L | L | L | L |
| Fukino et al. (60) | U | U | H | L | H | H | L | U |
| Hsu et al. (34) | L | L | H | L | L | U | L | L |
| Brown et al. (30) | L | L | H | L | L | U | L | L |
| Nagao et al. (61) | U | L | H | L | L | U | L | U |
| Hursel and Westerterp-Plantenga, (50) (A) | U | L | H | L | L | U | L | U |
| Hursel et al. (50) (B) | U | L | H | L | L | U | L | U |
| Frank et al. (24) | L | L | H | H | L | U | L | L |
| Nantz et al. (49) | U | U | H | H | L | U | H | U |
| Mohammadi et al. (62) | U | L | H | L | L | U | L | U |
| Sone et al. (44) | L | L | H | L | L | U | L | L |
| Hsu et al. (63) | L | L | H | H | L | U | L | L |
| Brown et al. (31) | L | L | H | L | L | U | H | L |
| Basu et al. (82) | L | L | H | H | H | U | H | L |
| Bogdanski et al. (77) | L | L | H | H | L | U | L | L |
| Suliburska et al. (41) | L | U | H | H | L | U | H | L |
| Wu et al. (43) (A) | L | L | H | H | L | U | L | L |
| Wu et al. (43) (B) | L | L | H | H | L | U | L | L |
| Miyazaki et al. (39) | L | U | H | L | U | U | L | L |
| Fukuzawa et al. (79) | L | U | H | H | U | U | H | L |
| Lasaite et al. (64) | U | L | H | H | L | U | L | U |
| Mielgo-Ayuso et al. (38) | L | L | H | H | L | L | L | L |
| Liu et al. (65) | U | L | H | H | L | U | L | U |
| Mirzaei et al. (72) | U | U | H | H | L | U | L | U |
| Chen et al. (32) | L | L | H | L | L | U | L | L |
| Dostal et al. (45) | L | L | H | L | L | U | L | L |
| Dostal et al. (46) | L | L | H | L | L | U | L | L |
| Borges et al. (66) | L | L | H | H | L | U | H | L |
| Lee et al. (83) | L | L | H | L | L | U | H | L |
| Lu and Hsu, (37) | L | L | H | H | L | H | L | L |
| Samavat et al. (53) | L | L | H | L | L | L | H | L |
| Nogueira et al. (78) | L | U | H | H | L | U | H | L |
| Mombaini et al. (76) | U | U | H | L | L | U | L | U |
| Kafeshani et al. (47) | U | L | H | L | L | U | H | U |
| Tabatabaee et al. (80) | L | U | H | H | L | U | L | L |
| Rostamian and Bijeh, (55) | U | U | H | H | U | U | L | U |
| Hussain et al. (81) | L | U | H | H | H | H | H | L |
| de Amorim et al. (70) | L | L | H | L | L | L | L | L |
| Amozadeh et al. (54) | U | L | H | L | H | U | L | U |
| Tadayon et al. (42) | L | H | H | H | L | U | H | L |
| Zandi Dareh Gharibi et al. (67) | U | U | H | H | H | U | L | U |
| Hosseini et al. (71) (A) | L | L | H | L | L | U | L | L |
| Hosseini et al. (71) (B) | L | L | H | L | L | U | L | L |
| Maeda-Yamamoto et al. (48) (A) | L | L | H | H | L | L | H | L |
| Maeda-Yamamoto et al. (48) (B) | L | L | H | H | L | L | H | L |
| Huang et al. (73) | L | L | H | H | L | U | L | L |
| Azizbeigi et al. (129) | U | U | H | L | U | U | H | U |
| Sobhani et al. (68) (A) | L | L | H | L | L | U | L | L |
| Sobhani et al. (68) (B) | L | L | H | L | L | U | L | L |
| Quezada-Fernández et al. (69) | L | L | L | H | L | U | L | L |
| Bagheri et al. (57) | U | L | H | L | L | U | L | U |
| Bagheri et al. (58) | U | L | H | L | L | U | L | U |
| Zhang et al. (56) | L | L | H | H | L | U | H | L |
| Bazyar et al. (130) | L | U | H | L | L | U | L | L |
L, low risk of bias; H, high risk of bias; U, unclear risk of bias.
*General low risk < 2 high risk, General moderate risk = 2 high risk, General high risk > 2 high risk.