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Asthma's changing prevalence.

and arterial bypass surgery will have no discernible effect on rates of amputation unless some of the additional revascularisations are in patients with critical limb ischaemia who would otherwise have received substandard care. The first priority in organising care for patients with occlusive arterial disease ofthe limbs must be to ensure that all patients with critical limb ischaemia have immediate access to specialist vascular units offering the full range of revascularising techniques, including distal bypass to crural and foot vessels. Bypass grafting to vessels below the knee is time consuming and expensive, but, even when reoperation is required, overall hospital costs are lower than for primary amputation and the huge community costs of long term care of amputees may be avoided entirely.4 Treatment for patients with intermittent claudication remains vexed. Patients with claudication often live in fear of amputation, although the likelihood of this is only about 1% a year5; in contrast, they seldom worry about their premature demise yet 40% will die within eight years,6 mostly from cardiac or cerebral events. Antiplatelet treatment with aspirin reduces mortality from vascular disease by one sixth7 and should be offered to all patients unless specifically contraindicated. Stopping smoking and adhering to a programme of regular exercise can provide symptomatic reliefofclaudication with no risk.8 In those patients who are still disabled despite conservative management the benefits of revascularisation, such as increased walking distance, should be carefully balanced against the risks of operation. Many patients will make an informed choice that transluminal angioplasty or bypass surgery is preferable to continuing disability, and they can legitimately expect that resources are available to meet their needs. The prevalence of intermittent claudication in men over 50 is at least 3%.9 Even if treatment is restricted to those who are most disabled the costs of meeting the latent demand will be considerable. JACK COLLIN Consultant Surgeon, Nuffield Department of Surgery, John Radcliffe Hospital, Oxford OX3 9DU