Walking speed meaningfully improves in patients with peripheral artery disease following supervised exercise therapy

Background: Supervised exercise therapy (SET) is a first-line treatment leading to significant improvement in walking distances and quality of life in patients with peripheral artery disease (PAD). The efficacy of SET is most commonly expressed by significant statistical improvement of parameters. This study examined the minimal clinically important difference (MCID) in walking speed in claudicating patients with PAD after SET. Methods: A total of 63 patients with PAD participated in a six-month SET program. Self-selected walking speed was measured before and after SET. Distribution and anchor-based approaches were used to estimate the MCID for small and substantial improvement from the Medical Outcomes Survey 36-item short Form questionnaire. Receiver operating characteristics curve analyses were performed to detect the threshold for MCID in walking speed after treatment. Results: The distribution-based method estimated 0.03 m/s as a small improvement and 0.08 m/s as a substantial improvement in walking speed after SET. Small and substantial improvements according to the anchor question “walking one block” were 0.05 m/s and 0.15 m/s, respectively. For the “climbing one flight of stairs” anchor question, 0.10 m/s was a small improvement. Receiver operating characteristics curve analyses identified an increase of 0.04 m/s and 0.03m/s for improvement based on walking one block and climbing one flight of stairs, respectively. Conclusions: The MCID can serve as a benchmark for clinicians to develop treatment goals and interpret clinically meaningful progress in the care of patients with PAD