Table 1.
General characteristics of included studies in the meta-analysis of DII and oral cancer risk.
| Study | Races/nationalities | Study design | Sample size(case/control) | Mean/median age(case/control) | Male/female(case/control) | DII measurement (no. of DII components) | E-DII | Years of duration | Study quality(NOS score) |
|---|---|---|---|---|---|---|---|---|---|
| Bao et al., 2020 (18) | Chinese | Matched case–control | 295/425 | 57.80/59.22 | 185/295 110/130 |
159-item FFQ (22) | Yes | 8 | 6 |
| Secchi et al., 2019 (19) | Argentinean | Matched case–control | 27/86 | Not reported | 15/46 12/40 |
127-item FFQ (25) | Yes | 3 | 6 |
| Mazul et al., 2018 (20) | American | Matched case–control | 195/1,372 | Not reported | 966/945 302/427 |
72-item FFQ (27) | Yes | 4 | 7 |
| Abe et al., 2018 (21) | Japanese | Matched case–control | 255/762 | 60/60 | 826/2,466 202/615 |
47-item FFQ (22) | No | 4.8 | 6 |
| Shivappa et al., 2017 (22) | Italian | Matched case–control | 506/2,492 | 58/58 | 756/1,497 190/995 |
78-item FFQ (31) | Yes | 17 | 7 |
DII, dietary inflammatory index; FFQ, food frequency questionnaires; E-DII, energy adjusted DII; NOS, Newcastle–Ottawa Quality Assessment Scale.