Trusts have complained that they cannot recruit and retain enough qualified clinical coders because Agenda for Change pay rates do not let them offer attractive wages.

At a conference for NHS information leads, one said: "Agenda for Change job descriptions do not even make any reference to payment by results. We cannot adequately pay these staff." Their complaints follow Audit Commission claims that errors in activity codes lead to erroneous bills for primary care trusts. Some PCTs say trusts deliberately "upcode" to inflate bills, although the commission, which audits coding, has no clear evidence of this.

NHS Information Centre principle case-mix consultant Stephen Cole said the staff shortage had been exacerbated by the commission, which "poached some of the better qualified coders from hospitals" and does not have to pay Agenda for Change rates. A spokeswoman for the commission denied this "NHS urban myth", pointing out problems predated its own coding work.

NHS Employers deputy director Gill Bellard said the shortage was not down to pay. Agenda for Change allowed trusts to pay coders a premium of up to 30 per cent of salary. "Any trust could pay [more] if they felt there was a need," she said.