| Items | Scores | Notes |
| A. Was an effective method of randomisation used? | Y = yes, e.g. use of random tables
? = no description of method
N = quasi‐randomised method only | To achieve 'Y', a random (unpredictable) assignment sequence is required. |
| B. Was the assigned treatment adequately concealed prior to allocation? | Y = method did not allow disclosure of assignment
? = small but possible chance of disclosure of assignment or unclear
N = quasi‐randomised or open list/tables | For example, a method using centralised (e.g. allocation by a central office unaware of subject characteristics) or independently‐controlled randomisation. |
| C. Were the outcomes of participants who withdrew described and included in the analysis (intention to treat)? | Y = no dropouts or withdrawals well described and accounted for in analysis.
? = withdrawals described and analysis not possible
N = no mention, inadequate mention, or obvious differences and no adjustment | |
| D. Were the outcome assessors blind to assignment status? | Y = effective action taken to blind outcome assessors
? = small or moderate chance of unblinding of outcome assessors
N = not possible, or not mentioned (unless double‐blind), or possible but not done | |
| E. Were the treatment and control groups comparable at entry? | Y = good comparability of groups, or confounding adjusted for in analysis
? = confounding small; mentioned but not adjusted for
N = large potential for confounding, or not discussed | The principal confounders considered were sex, age, previous overuse lower‐limb injury and prior physical activity profile. |
| F. Were the participants blind to assignment status after allocation? | Y = effective action taken to blind participants
? = small or moderate chance of unblinding of participants
N = not possible, or not mentioned (unless double‐blind), or possible but not done | |
| G. Were the treatment providers blind to assignment status? | Y = effective action taken to blind treatment providers
? = small or moderate chance of unblinding of treatment providers
N = not possible, or not mentioned (unless double‐blind), or possible but not done | |
| H. Were care programmes, other than the trial options, identical? | Y = care programmes clearly identical
? = clear but trivial differences
N = not mentioned or clear and important differences in care | Examples of clinically important differences in other interventions (co‐interventions) are those which could act as active measures for prevention of hamstring injuries: training programmes, advice on activity and etc. |
| I. Were the inclusion and exclusion criteria clearly defined? | Y = clearly defined
? = inadequately defined
N = not defined | To achieve 'Y', the inclusion or exclusion of individuals with a) previous hamstring injuries and b) previous exposure to trial intervention needs to be confirmed. |
| J. Were the interventions clearly defined? | Y = clearly defined interventions are applied with a standardised protocol
? = clearly defined interventions are applied but the application protocol is not standardised
N = intervention and/or application protocol are poorly or not defined | |
| K. Were the outcome measures used clearly defined? (by outcome) | Y = optimal
? = adequate
N = not defined, not adequate | To achieve 'Y', the method and strategy of data collection need to be clearly defined. |
| L. Were diagnostic tests used in outcome assessment clinically useful? (by outcome) | Y = clearly defined and best available tests are applied with a standardised protocol
? = clearly defined tests are applied but the application protocol is not standardised
N = tests and/or application protocol are poorly or not defined | |
| M. Is the surveillance active, and of clinically appropriate duration?(by outcome) | Y = active surveillance and appropriate duration
? = active surveillance, but inadequate duration
N = surveillance not active or not defined | |
| N. Was compliance of participants disclosed? | Y = compliance greater than 90% in each group after randomisation
? = compliance with allocated procedure reported
N = compliance not mentioned | Measures of compliance are likely to vary and thus the way of estimating the 90% compliance will depend on the measures used in individual trials. |
