The Weekend Effect - what's (un)knowable, and what next?

We do we know about the weekend effect? As Martin McKee puts it in an editorial on thebmj.com, "almost nothing is clear in this tangled tale"

In this roundtable, Navjoyt Ladher, Analysis editor for The BMJ is joined by some of the key academics who have published research and commented on the weekend effect to make sense of what we know and...