(7) Overall risk of bias
We will make explicit judgements about whether studies are at
high risk of bias, according to the criteria given in the Cochrane
Handbook for Systematic Reviews of Interventions (Higgins 2008).
With reference to (1) to (6) above, we will assess the likely magnitude
and direction of the bias and whether we consider it is likely
to impact on the findings. We will explore the impact of the level
of bias through undertaking sensitivity analyses - see Sensitivity
analysis.