Use of the walking impairment questionnaire as a measure of functional assessment

Background: A significant consequence of peripheral arterial disease (PAD) is an impaired functional capacity and deteriorated quality of life. Therefore, our study aimed to investigate the usefulness of a symptom questionnaire and walk tests for the determination of the functional capacity of patients with intermittent claudication. Patients and methods: The study included 53 patients (38 males) with stable claudication distance (50-300m). A detailed history and physical examination, ankle-brachial index (ABI), treadmill exercise test, and 6-minute walk test were performed and compared to walking impairment questionnaire (WIQ). Results: Claudication distance reported from patients' history and 6-minute walk test were significantly correlated with ABI (p=0.033, p=0.044). There were no significant correlations between ABI and treadmill walk test or WIQ. Results of WIQ were significantly correlated with the history and the most of performed walk tests: treadmill initial and maximal claudication distance (p=0.004 and 0.012, respectively) and 6-minute walk test (p=0.026). 6-minute walk test was correlated with maximal claudication distance of treadmill (p=0.018), but not with an initial claudication distance. Conclusions: The validity of WIQ is comparable to walk tests and represents the useful technique for the investigation of the functional capacity of patients with PAD. A self-report based on WIQ enables a longer period of observation. It should be routinely used as a basic diagnostic tool for the estimation of the functional capacity of PAD patients with stable intermittent claudication.