Validation of the Korean version of the walking impairment questionnaire in patients with peripheral arterial disease

PURPOSE: Intermittent claudication is the most common early symptom of peripheral arterial occlusive disease. Walking impairment questionnaire (WIQ) is a short, inexpensive, easy-to-complete questionnaire to assess intermittent claudication and can provide data of usual walking. The purpose of this study is to validate the new Korean version of WIQ. METHODS: Total 51 patients with claudication were enrolled. While 4 patients were dropped out, 47 patients with claudication into were divided groups based on the treatment received: surgery (n = 33) and medication (n = 14). The surgery group was subdivided into the bypass (n = 13) and intervention (n = 20) groups. WIQ score, ankle-brachial index (ABI), and treadmill test scores were assessed initially and after 12 weeks. RESULTS: The WIQ scores were significantly correlated with ABI and pain-free walking distance (PFWD) and maximum walking distance (MWD) in all groups (except for MWD in the intervention group). Speed and stair-climb scores (2 WIQ domains) were well correlated with ABI, PFWD, and MWD. Distance scores were mostly correlated with ABI, PFWD, and MWD in all groups except ABI in the bypass and intervention groups and MWD in the bypass group. Reproducibility was observed in all groups (intraclass correlation coefficient > 0.8). CONCLUSION: The Korean version of the WIQ is valid and reproducible, and can be effectively used to assess Korean patients with intermittent claudication.