On 1 April the NHS structure throughout the UK will look radically different to how it did just 23 months earlier when Labour came to power. A decade ago, the service protested shrilly against the pace of change instigated by the Thatcher reforms; the internal market took three years to concoct and launch. Labour's reforms are as far-reaching - yet even faster.

Apart from structural upheaval, the NHS will additionally face the challenge of establishing fruitful relationships with devolved governments in Scotland, Wales and Northern Ireland. In England, the arrival of 500 primary care groups will be the most obvious innovation, but let's not forget that the south east has also undergone a regional reorganisation - and remember, too, the scale of change quietly taking place on the ground in the form of trust mergers, as revealed in our survey this week.

In a little over two months, 49 trusts in England will merge. This follows the merger of 22 trusts in 1998. Scotland and Wales are witnessing a similar movement on a comparable scale. Yet minimal publicity has accompanied these seismic shifts; for the most part, public consultation has been uneventful. This is in marked contrast to proposals for service reconfigurations, which affect the future of much-loved bricks and mortar. These mergers are largely about rearranging managers - for the time being at least. Consequently, even the prospect that hundreds of posts will eventually be lost has not led to the appearance of banners in the streets.

The sceptical might therefore ask whether any of these mergers will affect how healthcare is delivered. The changes are predicted to save the NHS up to£20m in three years' time, but that in itself represents a retreat from the minimum savings the then health minister, Alan Milburn, stipulated in 1997 were acceptable from a merger.

While logic may dictate some of these plans, in reality mergers seldom fulfil expectations, either in the economy as a whole or the health service: research from the NHS Centre for Reviews and Dissemination suggests diseconomies of scale quickly impinge. Add in the management time absorbed in the process and the dent to staff morale which an uncertain future inevitably brings. Then contemplate the potential for mayhem when senior managers' attention is distracted during a time of financial difficulty for many trusts. You are faced with an inescapable question. Is it all worth it?