Patient power? The politics of patients' associations in Britain and America By Bruce Wood Open University Press 224 pages £19.99

This book is a welcome addition to the limited literature on patients' organisations. The study is valuable not least because it reveals limits to their power as much as their growing influence. The question mark in the title is important.

Based on substantial research by a political scientist, the study is rightly set in the mainstream as one of a series edited by Chris Ham for the Open University Press.

Bruce Wood has opened up the previously largely private world of specialised health charities. He documents the roles of more than 200 patient organisations, local and national, in the US and UK.

Wood sees the rapid growth of disease-related bodies in both countries, most in the past 20 years, as a remarkable feature of both societies. Though healthcare systems vary considerably, the dominant scene is of large amounts of voluntary activity, but also of specialisation and fragmentation and, in some cases, of competition between groups.

Wood makes comparisons between the US, where coalitions are rare, and the UK - and I declare an interest - where we are starting to make them effective.

His study raises key issues: are these economically efficient and politically effective bodies? Are they truly independent - or have they been colonised by big vested interests? Are they a signal of a more assertive patient or consumer? Do they truly influence what healthcare people receive?

Wood feels that while many UK associations do not describe themselves as political organisations, they are in fact seeking to influence attitudes and the distribution of healthcare resources - all political activities.

Readers who lack time to do their own research will find this a good shortcut to finding out answers to these questions and learning what this exploding number of organisations do. Virtually all bodies, Wood's research establishes, are concerned with long-term, chronic conditions.

This is where the commitment is - and where stronger users' voices are most needed.

Health service managers considering requests for support from local voluntary organisations will find the comparison between Manchester and St Louis of interest. In the US most local chapters have a rented office and at least one member of staff, unusual in the UK where home-based local branches are more normal. The conclusion is that this can lead to instability and burnout and that support is needed for local groups to reach their potential.

There are lessons to be learnt in my own sector from these findings, but also for the NHS nationally and locally. They should support groups that can provide services, pioneer new ways of working and help improve the quality of public services. The hand that feedeth may of course get bitten, but grin and bear it. And don't fall into the trap of saying 'they can't be representative'.

Effective patient organisations provide a unique perspective that the NHS would be foolish to ignore.

Judy Wilson Director, The Long-term Medical Conditions Alliance.