The independent review of the Read clinical codes programme has begun, and the results of the first phase should be published at the end of this month.

The National Audit Office reported earlier this year that no proper business case had ever been made for the codes and demanded a full review.

NHS chief executive Sir Alan Langlands promised the Commons public accounts committee that the review would be published by the end of this year.

The PAC said the review should look hard at alternatives, and the NHS Executive 'should not feel locked into using the Read codes because they have spent so much money on them'.

But the first stage of the review addresses only part of these demands.

Its initial terms of reference, released by health minister Alan Milburn after a parliamentary question by PAC member Maria Eagle, include an investigation into why the NHS needs a standardised clinical vocabulary and what other options exist.

The terms of reference were drawn up by the NHS Executive's Centre for Coding and Classification, which manages the Read programme.

And rather than being put out to tender to the private sector, this part of the the review was handed to Whitehall's own computer consultancy, the Central Computer and Telecommunications Agency.

The second and third stages of the review have not yet been defined, but Mr Milburn said they will assess the robustness of the Read codes against alternatives and set out ways for hospitals to evaluate the codes while using them.