Real-life adaptations in walking patterns in patients with established peripheral arterial disease assessed using a global positioning system in the community: A cohort study

Objective: Lower extremity peripheral arterial disease (PAD) is a chronic condition most commonly presenting with intermittent claudication (IC). IC limits walking ability and may negatively affect health-related quality of life. Treadmill assessment of maximal walking distance (MWD) is the gold standard to assess PAD symptom severity. Despite being a well-established and reproducible tool, it may be inappropriate (due to frailty or fear) for some patients and only describes maximal abilities for a single walk test. Global Positioning Systems (GPS) have been proposed as reliable and reproducible tool to measure total, mean and maximal walking distances in PAD patients, in the community setting. Using GPS our study attempted to explore what happens to the walking ability of patients with IC following no intervention under "real-life" conditions. Design and Methods: Using the GlobalSat DG100 GPS, forty-three patients (69±9yrs; 9 female; no invasive interventions or rehabilitation) undertook two 60-minute walking assessments, 6 months apart. Assessments took place in community spaces that had even terrain, no tall trees or buildings and were free from motorised vehicles. GPS-measured maximum walking distance was the main study outcome measure. Results: Over the 6-month period, patients demonstrated significantly shorter GPS-measured, mean (552m vs 334m; p=0.02) and maximum (714m vs 545m; p=0.04) walking distances, stopping also more frequently (9 v 5 times; p=0.03). Conclusions: Given the reported symptom progression we advocate early intervention (e.g. exercise interventions) combined with frequent patient monitoring in attempts to maintain or improve walking ability. Key Words: peripheral arterial disease; Global Position System; maximum walking distance; intermittent claudication; community assessments.