Free-living physical activity as an outcome measure in individuals with intermittent claudication

• Main Author: Clarke, Clare L.
• Published: Glasgow Caledonian University 2013
• Subjects: 616.1
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.636803

Introduction: Intermittent claudication (1C) is the most common clinical manifestation of Peripheral Arterial Disease (PAD). It is muscular leg pain experienced during free-living walking that leads to fragmented walking patterns in those affected. Existing clinical outcome measures primarily provide physiological information with little focus on its functional impact within the free-living environment. Purpose: The primary aim of this thesis was to investigate if free-living Physical Activity (PA) monitoring could be used as an outcome measure in the clinical assessment of individuals with le. Method: A cross-sectional, observational study was undertaken to develop and test novel P A outcome measures specific to the walking limitations experienced by those with IC. Seven-days continuous ambulatory monitoring was carried out using the activPAL™ PA monitor on 71 individuals with IC; 38 of which were re-measured after the 6 months intervention period. This data was used to develop novel P A outcome measures, concentrating on event-based analysis, to determine differences between 30 individuals with IC and matched controls from the Glasgow Caledonian University PA database. Selected outcomes were then correlated to existing clinical measures and change over 6 months for all participants with IC. Results: Novel PA outcomes based upon fragmentation of, and cadence during, free-living walking were developed that have shown promising potential to be effective adjunct measures to clinical measures for those with le. Of particular importance is the development of the Event-Based Claudication Index (EBCI), which was able to differentiate between those with IC and controls in terms of identifying a more fragmented walking pattern in those with le. The EBCI provides an objective PA outcome measure that is specifically tailored to the unique walking limitations experienced by individuals with le. With the exception of the HADS anxiety sub-scale, all event-based PA outcomes correlated with existing clinical measures, again showing promise this time in terms of clinical relevance. In addition, event-based PA analysis appeared to have a higher sensitivity to change over time compared with analysis of the more universally used volume-related measures such as time spent walking and/or standing. Discussion/Conclusion: Free-living PA monitoring may be a potentially useful adjunct measure to existing clinical measures of IC as it provides an objective outcome specifically tailored to the walking limitations experienced by those individuals with IC. Such an outcome measure could significantly enhance the clinicians' ability to objectively determine the effectiveness of interventions in both clinical and research environments.