Table 2.

Reliability and percent agreement of individual QA-SIVAS items

No.	QA-SIVAS scale item	Base rate	Free-marginal kappa	Kappa (95% CI)	Percent exact agreement
1	Objective stated	100	1.00	1.00–1.00	100
2	A representative sample was chosen	40	0.68	0.42–0.93	84
3	Information about sample is included	0	1.00	1.00–1.00	100
4	Information about video source and quality of the footage are included	13	0.68	0.43–0.93	84
5	Applied methods are described comprehensively	95	1.00	1.00–1.00	100
6	A systematic approach to video analysis was chosen	94	0.94	0.81–1.00	96
7	Medical report information is included	29	1.00	1.00–1.00	100
8	Background/expertise of rater(s) is stated	49	0.81	0.61–1.00	90
9	Findings are observed by more than one researcher	70	0.94	0.81–1.00	96
10	A control group is included	14	1.00	1.00–1.00	100
11	A quantitative biomechanical analysis was conducted using validated methods	13	0.86	0.67–1.00	92
12	The main results of the study are clearly described	95	0.87	0.70–1.00	93
13	Absolute numbers or proportions of injury cases (for each/the main outcome) are reported	95	0.87	0.70–1.00	93
14	Details about the injury context are included	92	0.94	0.81–1.00	96
15	Example screenshots/video frames are included	76	1.00	1.00–1.00	100
16	Findings are discussed within the context of the current evidence	100	1.00	1.00–1.00	100
17	Clinical/practical implications of the results are discussed	90	0.81	0.61–1.00	90
18	Limitations of the study are addressed	100	1.00	1.00–1.00	100

Base rate refers to the percentage of ratings that were answered with yes/present out of 63 ratings per scale item (21 studies, 3 reviewers)