Stephenson and colleagues have written a clear and well referenced article, taking the view that urban prehospital thrombolysis is unlikely to be either clinically or cost effective.¹ Some of their arguments in support of this assertion, such as the idea that urban prehospital times are very short or that complications are a significant concern, I have already addressed. We both agree that one of the main problems in this field is a lack of research, and until adequately powered studies of paramedic administered urban prehospital thrombolysis are published we must rely upon educated guesswork and extrapolation. Such studies will also …