'It is notable that not one of the 13 early achiever sites comes from NHS London or NHS East of England'

From 18 months to 18 weeks will be the success by which the Blair health reforms are judged, or so the man himself hopes. The 18-week referral to treatment target remains highly challenging because of continuing cloudiness over just how much of a squeeze the diagnostics bottleneck will prove.

As our cover feature in this.week's issue.(pages 22-24) reports, 13 'early achiever' sites have taken the pledge to hit the target a year early. Often helped by the NHS Institute for Innovation and Improvement and NHS Elect, these pioneers are still happy to admit it will be a struggle. Even the man who helped create the 18-week programme while at the Department of Health and who is now running one of the pilots describes just how tough the measurement and management issues are.

There are some common headaches between the sites: historically 'ropey' data, variation within as well as between specialisms, and continuing concerns around orthopaedics.

Although even these high performers have a long way to go there are already impressive results. Bolton Hospitals trust, for example, has managed to cut endoscopy waits from 44 weeks to six.

How big will the variation in performance be? At least one strategic health authority area should be capable of achieving 100 per cent compliance before the end of 2007, and probably at a relatively small additional cost compared to waiting until the end of the following year.

On the other hand, it is notable that not one of the 13 early achiever sites comes from NHS London or NHS East of England.

As with other important reforms, success cannot be measured by the speed of the front-runners but by how far and for how long the tail drags.