Comparison of reported symptoms to those produced by treadmill testing in patients with claudication suspected of arterial origin

AIM

We aimed at comparing lower limb symptoms reported by history to those observed during a standard treadmill test.

METHODS

We retrospectively studied symptomatic patients referred over a three years period for suspected arterial claudication and used the Edinburgh claudication questionnaire before exercise and symptoms observed on a treadmill. We confronted, right and left, proximal (lower-back thigh or buttocks) and distal (leg or foot) lower-limb symptoms before and during treadmill exercise. Results are reported as mean ± standard deviation for percentage and 95% confidence interval and Kappa statistics are performed.

RESULTS

Of 795 patients with claudication, aged 63 ± 12 years, treadmill test resulted in 715 reporting lower-limb symptoms on treadmill. Cohen's Kappa for the site-specific analysis of symptoms by history vs. symptoms on treadmill was 0.509 ± 0.21 (P < 0.01), showing a moderate agreement. Nevertheless, symptoms on treadmill reproduced, at least partly, symptoms by history in 675 (84.9% 95CI: 82.3-87.2) of patients, although symptoms on treadmill were strictly of the same localizations as symptoms by history in only 378 (47.6% 95CI: 44.1-51.0) of all studied patients. Last, 279 patients (35.1% of all patients) reported non limb symptoms on treadmill.

CONCLUSION

Although on a site by site basis the concordance of symptoms by history to symptoms by treadmill is moderate, most patients reproduced their usual symptoms on treadmill. Age does not seem to impair the concordance. Last, beyond the sole measurement of maximal walking capacity, treadmill frequently unmasks non-limb limiting symptoms that may require clinical attention.