January 3.

In seeking to defend his criticisms of the hospital ''league tables'',

Iain Glen of the SNP puts forward a bizarre argument (January 3).

If the clinicians at the Western General Hospital, Glasgow, did indeed

dissociate themselves ''from any valid interpretation'' of the results,

this merely demonstrates that they care more for professional solidarity

than they do for statistics.

Dr Glen's view is on a par with those who reject all the statistical

evidence that smoking causes lung cancer, or that accidents at 30mph

cause fewer deaths than those at 50mph. What on earth are the ''sources

of error'' he refers to? What is ''statistical variance'' (it is clearly

not ''variance'', a technical term in statistics, and one that Dr Glen

has probably never heard of)?

I presume that if Dr Glen denies any validity to the hospital figures,

which tell us about events that actually happened, he would not give the

time of day to an opinion poll (which of course asks a hypothetical

question) showing that, say, 40% of those questioned said they would

vote SNP.

Andrew Anderson,

Granton Lodge,

179 Granton Road,

Edinburgh.