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| Study ID | Methodological filters | |||
| Filter 1 | Filter 2 | Filter 3 | Filter 4 | |
| Fraser 2006 | Precision Terms Filters | Specificity Terms Filters | NA | NA |
| Furlan 2006 | Fixed method A | Fixed method B | Progressive method (CV) | Progressive method (CV or TW) |
CV: controlled vocabulary; TW: text words
