Perceived Versus Objective Change in Walking Ability in Peripheral Artery Disease: Results from 3 Randomized Clinical Trials of Exercise Therapy

Abstract

Background In people with lower‐extremity peripheral artery disease, the effects of exercise on patient‐reported outcomes remain unclear. Methods and Results Four hundred four people with peripheral artery disease in 3 clinical trials were randomized to exercise (N=205) or a control group (N=199) and completed the 6‐minute walk and the Walking Impairment Questionnaire distance score (score 0–100, 100=best) at baseline and 6‐month follow‐up. Compared with the control group, exercise improved 6‐minute walk distance by +39.8 m (95% CI, 26.8–52.8, P<0.001) and the Walking Impairment Questionnaire distance score by +7.3 (95% CI, 2.4–12.1, P=0.003). In all, 2828 individual Walking Impairment Questionnaire distance score questions were completed at baseline and follow‐up. Among participants who perceived no change in ability to walk 1 or more distances between baseline and follow‐up, 6‐minute walk improved in the exercise group and declined in the control group (+26.8 versus −6.5 m, P<0.001). Among participants who perceived that their walking ability worsened for 1 or more distances between baseline and follow‐up, the 6‐minute walk improved in the exercise group and declined in the control group (+18.4 versus –27.3 m, P<0.001). Among participants who reported worsening calf symptoms at follow‐up, the exercise group improved and the control group declined (+28.9 versus −12.5 m, P<0.01). Conclusions In 3 randomized trials, exercise significantly improved the 6‐minute walk distance in people with peripheral artery disease, but many participants randomized to exercise reported no change or decline in walking ability. These findings suggest a significant discrepancy in objectively measured walking improvement relative to perceived walking improvement in people with peripheral artery disease. Registration Information clinicaltrials.gov. Identifiers: NCT 00106327, NCT 01408901.

Keywords

• exercise
• intermittent claudication
• patient‐reported outcome measures
• peripheral artery disease