The efficacy of exercise in preventing injury in adult male football: a systematic review of randomised controlled trials

Sports Medicine - Open

Table 3 Summary of risk of bias scores [20], reported in line with Rushton et al. [49]

References	Components of risk of bias ^a						Overall	Comments, high-risk components
References	1	2	3	4	5	6	Overall	Comments, high-risk components
Askling et al. [52]	U	U	H	U	U	U	High 1 Unclear 5 Low 0	High-risk components: 1 No participant, intervention provider, or outcome assessor blinding
Engebretsen et al. [12]	U	U	H	L	U	U	High 1 Unclear 4 Low 1	High-risk components: 1 No participant, intervention provider, or outcome assessor blinding
Fredberg et al. [51]	U	U	H	U	U	U	High 1 Unclear 5 Low 0	High-risk components: 1 No participant, intervention provider, or outcome assessor blinding
Hölmich et al. [53]	L	U	H	U	U	L	High 1 Unclear 3 Low 2	High-risk components: 1 No participant, intervention provider, or outcome assessor blinding
Mohammadi [55]	U	U	U	L	U	H	High 1 Unclear 4 Low 1	High-risk components: 1 Inadequate reporting of many aspects of study design
Petersen et al. [50]	L	U	H	L	L	L	High 1 Unclear 1 Low 4	High-risk components: 1 No participant, intervention provider, or outcome assessor blinding
Tropp et al. [56]	U	U	U	L	U	H	High 1 Unclear 4 Low 1	High-risk components: 1 Inadequate reporting of many aspects of study design
van Beijsterveldt et al. [54]	L	U	H	L	U	U	High 1 Unclear 3 Low 2	High-risk components: 1 Insufficient participant, intervention provider, and outcome assessor blinding

^aComponents of risk of bias: 1, random sequence generation; 2, allocation concealment; 3, blinding of participants, personnel, and outcome assessors; 4, incomplete outcome data; 5, selective reporting; 6, other bias. Levels of risk of bias: H, high risk of bias; U, unclear risk of bias; L, low risk of bias.