Discordance of patient-reported outcome measures with objectively assessed walking decline in peripheral artery disease

Objective: Among people with peripheral artery disease (PAD), perceived change in walking difficulty over time, compared with people without PAD, is unclear. Among people reporting no change in walking difficulty over time, differences in objectively measured change in walking performance between people with and without PAD are unknown. Methods: A total of 1289 participants were included. Eight hundred seventy-four participants with PAD (aged 71.1 ± 9.1 years) were identified from noninvasive vascular laboratories and 415 without PAD (aged 69.9 ± 7.6 years) were identified from people with normal vascular laboratory testing or general medical practices in Chicago. The Walking Impairment Questionnaire and 6-minute walk were completed at baseline and 1-year follow-up. The Walking Impairment Questionnaire assessed perceived difficulty walking due to symptoms in the calves or buttocks on a Likert scale (range, 0-4). Symptom change was determined by comparing difficulty reported at 1-year follow-up to difficulty reported at baseline. Results: At 1-year follow-up, 31.9% of participants with and 20.6% of participants without PAD reported walking difficulty that was improved (P <.01), whereas 41.2% vs 55%, respectively, reported walking difficulty that was unchanged (P <.01). Among all reporting no change in walking difficulty, participants with PAD declined in 6-minute walk, whereas participants without PAD improved (−10 vs +15 meters; mean difference, −25; 95% confidence interval, −38 to −13; P <.01). Conclusions: Most people with PAD reported improvement or no change in walking difficulty from calf or buttock symptoms at one-year follow-up. Among all participants who perceived stable walking ability, those with PAD had significant greater declines in objectively measured walking performance, compared with people without PAD.