It's a bit of a long shot but I'm hoping that someone might know if this study exists.
I'm looking for something that sets out the cost/benefit of RR vs other interventions. A sort of 'RR costs x per child and results in average gains of y months in reading and spelling age; intervention z costs x per child and results in gains of y months in reading and spelling age'
I've got plenty of stuff about the limitations of RR own research, how gains aren't held in the long term and how the short term gains are less than other interventions. But other than the fact that it is expensive it's difficult to see how it compares financially to other interventions.