If evidence-informed policy works in practice, does it matter if it doesn’t work in theory?

English Professionals and policy makers sometimes do more harm than good when they intervene in the lives of other people. This should prompt humility and efforts to ensure that policies and practices are informed by rigorous, transparent, up-to-date evaluations of relevant empirical evidence. Systematic reviews of relevant evidence must be designed to minimise the likelihood of confusing the effects of interventions with the effects of biases and chance. Systematic reviews are essential, although insufficient, for informing policies and practice. Critiques of this approach based solely on theory are unhelpful in efforts to protect the public from harmful and useless interventions.