The Campbell Collaboration’s systematic review of school-based anti-bullying interventions does not meet mandatory methodological standards

Table 2 Reliability of ratings of SOR bias for 41 RCTs^a

	Our SOR ratings based on criteria stated in the review ([6] p. 19)
SOR ratings in the review ([6] Appendix B)	Low risk	Unclear or unclear/high	High risk
Low risk	1	36	1
Unclear	0	2	0
High risk	0	1	0

^aFor 41 trials with two sets of ratings: proportion of agreement = 7% (3/41); Cohen’s kappa = 0.003

ISSN: 2046-4053