RADIAL meta-analysis: following the rules usually pays off

We thank Dr. de Souza and colleagues for their careful and thorough evaluation of our recent patient-level meta-analysis (1). They have provided an excellent summary of our methods and findings which we will not spend time repeating here. Instead, we will give an adequate reply to their critique. The issues raised in their paper are important and deserve careful consideration. Our response will address the foremost of their concerns which is the exclusion of the Örebro study by Dreifeldt et al. from our analysis.