Beyond the Patient's Report: Self-Reported, Subjective, Objective and Estimated Walking Disability in Patients with Peripheral Artery Disease.

Nicola Lamberti,Paolo Zamboni,Vincenzo Gasbarro,Luca Traina,Fabio Manfredini,Giovanni Piva,Lorenzo Caruso,Valentina Ficarra

doi:10.3390/diagnostics11111991

Abstract

Among patients with peripheral artery disease, an altered estimation of walking ability reported to the physician may influence the choice of treatment. We compared claudication distance (CD) values reported by patients or assessed by validated protocols to elaborate a formula capable of estimating more reliable values. Three hundred fifty-nine patients with claudication were measured at the time of entry into a rehabilitation program. Walking performance was obtained by patients’ reports (self-reported claudication distance, SR-CD) and was directly assessed to determine the claudication and maximal walking distance by the 6-min test (6-CD and 6-MWD) and an incremental treadmill test (T-CD and T-MWD). The degree of muscle deoxygenation was objectively determined at the calf by near-infrared spectroscopy (NIRS) during the treadmill test. Among the 289 subjects analyzed, SR-CD exceeded both 6-CD and T-CD (+155 and +182 m, respectively). SR-CD was moderately correlated with T-CD (r = 0.30), 6-CD (r = 0.32), and 6-MWD (r = 0.29) but not with muscle deoxygenation per meter walked, unlike T-CD and 6-CD. A formula adjusted for the presence of diabetes reduced patient overestimation by 92%. The patient’s reported claudication distance was generally overestimated compared to objective measures, and it was made more reliable through a corrective factor for easy use in a clinical setting.

Highlights

Peripheral artery disease (PAD) is a widespread condition that is highly prevalent in elderly individuals and may significantly limit functional capacity [1]
The degree of muscle deoxygenation was objectively determined at the calf by near-infrared spectroscopy (NIRS) during the treadmill test
Self-reported claudication distance (SR-claudication distance (CD)) was moderately correlated with treadmill claudication distance (T-CD) (r = 0.30), 6-min claudication distance (6-CD) (r = 0.32), and 6-MWD (r = 0.29) but not with muscle deoxygenation per meter walked, unlike T-CD and 6-CD

Summary

Introduction

Peripheral artery disease (PAD) is a widespread condition that is highly prevalent in elderly individuals and may significantly limit functional capacity [1]. Previous studies have evaluated the reliability of patients’ responses by comparing the report of walking autonomy with data estimated by validated questionnaires or assessed by laboratory- or communitybased walking tests [6,9,10,11,12,13,14,15], with mixed results These studies were performed in a limited number of patients and often compared the individual report with data collected by validated outcome measures, which were potentially affected by subjective perception [15]. Near-infrared spectroscopy (NIRS) has made possible the noninvasive study of local muscle metabolism and the objective and dynamic quantification of the degree of muscular deoxygenation in individuals, including PAD patients [8,22,23,24,25] This objective parameter might offer further information when compared with patient reports and with traditional walking tests based on patients’ subjectivity

Results

Discussion

Conclusion