Known by a number

SIR – The suggestion by Dr William Ward (Letters, August 28) that we can overcome the problem of “ghost patients” through a national identity card system, with everyone receiving a unique number, is somewhat strange.

We already have two unique numbers: the 10-digit NHS identifier and the three-letter, six-digit National Insurance number. Do we really need yet another ID number?

Richard Morris Lutterworth, Leicestershire