What were the reasons for downgrading the quality of the evidence?
The main reasons for downgrading the quality of the evidence were a lack of detail about randomisation/allocation concealment, imprecision due to small study size, performance bias in quality of life assessment due to lack of blinding, selective reporting of quality of life data, potential selection bias in the studies, and the fact that many of the studies were more than twenty years old and not in the context of current NHS practice.