Claudication distance is poorly estimated and inappropriately measured.

BACKGROUND: Claudication distance is the commonest measure of the disability caused by lower-limb occlusive arterial disease. The accuracy of claudication distance as a surrogate for handicap has been assessed.
METHODS: Seventy patients who attended a specialist vascular clinic with intermittent claudication were studied prospectively. Patients were asked to estimate their claudication distance and maximum walking distance before undergoing both a patient-controlled corridor walk and a fixed-speed treadmill walk.
RESULTS: The claudication distance reported by patients bore little relation to the distance recorded in the medical correspondence. There was no correlation between the estimated distance and the actual distance walked on either a patient-controlled corridor walk or a fixed-speed treadmill walk. Most patients were able to walk substantially further at their own speed on the corridor than on the treadmill at a slower speed.
CONCLUSION: Claudication distance is spuriously estimated, inaccurately reported, falsely recorded, inappropriately measured and usually misinterpreted. It is of little value in judging the need for treatment. Objective measures of the handicap caused by the disability of reduced walking distance are required if rational management decisions are to be made.