A reply

摘要

We agree with many ot the points raised in Sanders et al.'s excellent letter. Their data on turnover (or 'down') time confirm the points we make in our reply to Cook's letter [1, 2]. Their original turnover time of 23 min was clearly 'unusually long' and so reducing this enabled them to make time savings to accommodate extra cases. This contrasts with the more common scenario where turnover times are already close to approximately 10-15 min, when it is unlikely that further reductions will facilitate extra cases