In defence of reviews of small trials: underpinning the generation of evidence to inform practice

The value of systematic reviews of small trials has recently been questioned.[1] Contrary to the arguments of others who maintain that systematic reviews are crucial to avoiding waste[2], Roberts and Ker contend that systematic reviews of small trials "cause research waste" primarily because such reviews fail "to acknowledge the unreliability of small, single-centre trials".[1] We suggest that there is considerable awareness of the challenges of using small trials and that adherence to
standard Cochrane methods helps counter the concerns surrounding the inclusion of small trials. This editorial illustrates why Cochrane Reviews of small trials are of value and how they can act as important grounds and platforms for trials that are large and robust enough to inform practice. We look at recently updated Cochrane Reviews on the treatment of an increasingly common fracture and the commonest impairment after stroke.[3,4]