Table 2 Critical appraisal criteria established on the basis of the framework proposed by Vandenberg et al. [37] and the knowledge of the experts in the review team (C stands for Control, E for Exposed, B for Before, A for After, and N/A for non-applicable)
Source of bias | Criteria | Low risk of bias | Medium risk of bias | High risk of bias |
|---|---|---|---|---|
Experimental design | What is the experimental design? | CE BA BACE | Unknown | |
Is the experiment replicated (at least one replicate; a replicate is not exposed to water in contact with the other replicates) | Yes | No Unknown (assumed to be No) | ||
Exposure | If a solvent is used, is a solvent control present? | Yes N/A | No Unknown (assumed to be No) | |
Have effective exposure concentrations been measured? | Yes | No Unknown (assumed to be No) | ||
Selection | Are there differences at baseline between groups C and E? (including difference in exposure environment, difference in biological model, difference in the set of individuals allocated to each group) | No N/A (for BA design) | Yes but the effect is controlled and null For in situ studies: yes but an attempt to minimize differences is made | Yes (detail) Unknown (assumed to be Yes) |
Performance | Are there differences in the way groups C and E (or B and A) are treated throughout the experiment? | No | Yes (detail) Unknown (assumed to be Yes) | |
Detection | Are there differences in the way the outcomes of groups C and E (or B and A) are assessed? | No | Yes (detail) Unknown (assumed to be Yes) | |
Exclusion | Are there differences in the way groups C and E (or B and A) are removed from the study? | No | Yes (detail) Unknown (assumed to be Yes) | |
Other | Is there another source of bias? (e.g., reporting bias, insufficient description of the methods, an unforeseen event that occurred during the experiment) | No | Yes minor (detail) | Yes major (detail) |