We welcome the government's decision that anti-dementia drugs should continue to be available to National Health Service patients. The decision that the NHS will pay for proper treatment for those with Alzheimer's disease and other forms of dementia is right. More important, it is a triumph for the open process which now governs decisions about drug-spending priorities in Britain.

As minister Stephen Ladyman explains in The Observer today, his concerns about plans to withdraw the anti-dementia drugs were less on the issue of the £54 million a year cost than on the way in which the National Institute for Clinical Excellence (Nice) reached its decision. Nice issued guidance stating that, even though the the cost per patient was only £2.50 a day, the medication was not cost-effective. Their decision was based on a methodology which many experts now consider to be flawed. When Nice was set up six years ago, it was given the responsibility for taking both clinical and cost-effectiveness into account when deciding whether treatment should be available to NHS patients.

In this case, the method used to weigh the value of such drugs placed too little value on an improved quality of life for older people and gave insufficient consideration to how carers' lives are improved by having partners or parents who, thanks to the drugs, can feed themselves and even go out alone.

Undertaking appraisals of drugs is not easy, given the emotive nature of the work and the pressure from patients' groups and pharmaceutical companies. Other countries are rightly envious that, since the introduction of Nice, experts rather than politicians consider the evidence on efficacy and publish their conclusions. Anyone, however humble, can challenge the results. The decision on anti-dementia drugs shows the system works.