Free-living Physical Activity as a Novel Outcome Measure in Patients with Intermittent Claudication

Objective: To develop a method of event-based analysis that quantifies the fragmented nature of walking bouts in individuals with intermittent claudication [IC] and compare outcomes with age and gender-matched healthy controls. Design: Cross-sectional. Materials: The activPAL(TM) physical activity monitor. Methods: 7-day physical activity patterns were compared between individuals with IC (n = 30) and controls matched for age and gender (n = 30). The ratio of the number of walking events to upright events was calculated to provide an event-based claudication index (EBCI) that represented the fragmented nature of walking bouts commonly reported in those with IC. Results: Individuals with IC had a greater EBCI than age matched controls indicating a more fragmented walking pattern (5.8 +/- 2.0 vs. 7.7 +/- 3:1, p < 0.01). The difference between groups was more pronounced when the EBCI was calculated from upright events that included >400 steps (23.4 +/- 11.3 vs. 35.8 +/- 14.2, p < 0.01). Conclusion: The classic fragmented stop/start walking pattern universally described by individuals with IC can be quantified using the EBCI. This method of measurement potentially provides a novel method of assessing the effectiveness of clinical interventions for this patient group. Crown Copyright (C) 2012 Published by Elsevier Ltd on behalf of European Society for Vascular Surgery. All rights reserved. Article history: Received 8 August 2012, Accepted 21 November 2012, Available online 20 December 2012