Table 2 Numerical scoring system used to allocate a score-based grade for the overall risk of bias in each of the twenty-six reviewed studies
Studies | Randomisation sequence generation | Allocation concealment | Blinding of participants and personnel | Blinding of outcome assessment | Incomplete outcome data | Selective reporting | Other bias | Overall `risk of bias' category |
|---|---|---|---|---|---|---|---|---|
Boothe et al. [11] | 1 | 1 | 1 | 2 | 2 | 2 | 2 | Low/moderate (11) |
Primary investigator could potentially influence the treatment. | ||||||||
Chung et al. [24] | 3 | 3 | 3 | 3 | 1 | 2 | 2 | Moderate/high (17) |
Research support but unclear if it was financial. | ||||||||
Cunningham et al. [29] | 3 | 3 | 3 | 3 | 2 | 2 | 2 | Moderate/high (18) |
Conference abstract | ||||||||
Dewey et al. [18] | 3 | 3 | 3 | 3 | 2 | 2 | 2 | Moderate/high (18) |
Less than 6 months study duration. | ||||||||
Dewey et al. [19] | 3 | 3 | 3 | 3 | 2 | 2 | 1 | Moderate/high (17) |
EMEA pseudo-trial [13] | 1 | 2 | 1 | 3 | 1 | 2 | 2 | Low/moderate (12) |
The follow up assessment of efficacy was not blinded. Different drug formulations were used compared to the final formulation. | ||||||||
Govendir et al. [21] | 3 | 3 | 3 | 3 | 2 | 2 | 3 | High (19) |
A few cases were treated by the referring vets. The study had financial support. Less than 6 months study duration. | ||||||||
Heynold et al. [36] | 3 | 3 | 3 | 3 | 2 | 2 | 3 | High (19) |
The study had financial support but unclear if it influenced the results. Less than 6 months study duration. | ||||||||
Kiviranta [17] | 3 | 3 | 3 | 3 | 2 | 2 | 1 | Moderate/high (17) |
Löscher et al. [26] | 3 | 3 | 3 | 3 | 2 | 2 | 3 | High (19) |
Part of the study was retrospective | ||||||||
Morton et al. [31] | 3 | 3 | 3 | 3 | 2 | 2 | 3 | High (19) |
A few cases were treated by the referring vets. The study had financial support but unclear if it influenced the results. | ||||||||
Muñana et al. [12] | 1 | 1 | 1 | 1 | 2 | 2 | 2 | Low/moderate (10) |
The study had financial support but unclear if it influenced the results. | ||||||||
Nafe [25] | 3 | 3 | 3 | 3 | 2 | 2 | 3 | High (19) |
Less than 6 months study duration. | ||||||||
Pearce [32] | 3 | 3 | 3 | 3 | 2 | 2 | 2 | Moderate/high (18) |
Platt et al. [22] | 3 | 3 | 3 | 3 | 1 | 2 | 3 | Moderate/high (18) |
Less than 6 months study duration. | ||||||||
Podell et al. [33] | 3 | 3 | 3 | 3 | 2 | 2 | 3 | High (19) |
Retrospective nature of study. | ||||||||
Rieck et al. [27] | 3 | 3 | 3 | 3 | 2 | 2 | 3 | High (19) |
Part of the study was retrospective | ||||||||
Ruehlmann et al. [35] | 3 | 3 | 3 | 3 | 1 | 2 | 3 | Moderate/high (18) |
Part of the study was retrospective. No clarification of statistical analysis | ||||||||
Schwartz-Porsche [28] | 3 | 3 | 3 | 3 | 2 | 2 | 2 | Moderate/high (18) |
Schwartz-Porsche et al. [15] | 2 | 2 | 3 | 3 | 2 | 2 | 2 | Moderate/high (16) |
The study had research support but unclear if it influenced the results. No clarification of statistical analysis | ||||||||
Schwartz-Porsche et al. [30] | 3 | 3 | 3 | 3 | 2 | 2 | 1 | Moderate/high (17) |
Steinberg [23] | 3 | 3 | 3 | 3 | 2 | 2 | 2 | Moderate/high (18) |
Conference abstract | ||||||||
Tipold et al. [14] | 1 | 2 | 1 | 1 | 1 | 2 | 3 | Low/moderate (11) |
Statistical analysis was conducted before unblindingonly on the per-protocol population and not on the intent-to-treat population. A high and unbalanced population of animals was excluded. The reasons for exclusion were in many cases treatmet-related (post-randomization bias). Conflict of interest about imepitoin reported. | ||||||||
Trepanier et al. [34] | 3 | 3 | 3 | 3 | 2 | 2 | 2 | Moderate/high (18) |
Some samples were submitted by the referring vets. | ||||||||
Volk et al. [16] | 3 | 3 | 3 | 3 | 1 | 2 | 3 | Moderate/high (18) |
The study had financial support but unclear if it influenced the results. Part of the study was retrospective | ||||||||
Von Klopmann et al. [20] | 3 | 3 | 3 | 3 | 2 | 2 | 3 | High (19) |
Less than 6 months study duration. |