Nigel - Like all the other people contributing to this thread I don't have any access to the actual information about NHS costs, so anything I state is purely speculation based on my past observations.
I am well aware that on a Friday or Saturday night, an A&E department will be treating a higher number of patients there as the result of drink related injuries, but I still maintain that the numbers from the BBC are likely to be based on flawed or skewed data.
Hospital running costs are not based on the totally unpredictable number of attendees in Accident & Emergency and staffing levels are not based on the statistically expected number of drunks (I think you will find that weekend night-time staffing levels are usually lower than during office hours).
Whatever the number of drunks, there will be heart attacks, house fires, traffic pile-ups, accidental poisonings, kids falling off climbing frames and any number of other reasons for A&E to be needed, hence the ongoing Fixed Costs.

I suppose what I'm saying is don't just read the "tabloid" headlines. The reality is nearly always something entirely different.
Quack!
Geoff.