AbstractPeripheral Arterial Disease (PAD) is a marker of systemic atherosclerosis and is associated with a three to six fold increased risk of death from cardiovascular causes. Furthermore, it is typically asymptomatic and under-diagnosed; this has resulted in escalating calls for the instigation of primary care PAD screening via ankle brachial index (ABI) measurement.
The concept of PAD screening is, however, contentious with significant ambiguity relating to its feasibility and efficacy. Hence, the aim of the research detailed within this thesis was to provide a contemporary and comprehensive investigation of PAD screening within the primary care setting. This was achieved via four inter-related studies:
1. PIPETTE Study (n=368) – a prospective observational study involving a trial of a proposed PAD screening strategy investigated (i) how PAD screening should be targeted and (ii) if individuals found to have PAD benefited from their diagnosis.
2. IVAM study (n=12) – a study designed to (i) validate PAD diagnoses in the PIPETTE study and (ii) function as a pilot study for future research investigating the accuracy of ABI measurement in primary and secondary care.
3. DUAL study (n=727 measurements) – a comparative study of the traditional method used for ABI measurement (Doppler ultrasound) versus automated ABI equipment.
4. GP survey – an all-Wales general practice survey regarding the current utility of the ABI within this setting.
Results enabled identification of a screening target population which would result in a highly efficient PAD screening strategy. However, if the Doppler ABI continues to be utilised as the screening tool of choice, then prior to the formal implementation of PAD screening, there is a need for a robust ABI training programme with standardised methodology in order to optimise accuracy and consistency of results.
An automated ABI device demonstrated potential to address feasibility issues associated with PAD screening with the ABI via a reduced need for operator skill and significantly reduced screening time. However, further refinement of the device is required to improve its diagnostic accuracy.
The value of PAD screening, from a cardiovascular perspective, has been shown to be questionable, as a current cardiovascular risk assessment algorithm (QRISK2) also identified high risk in a large majority of individuals found to have PAD.
|Date of Award||Jan 2015|
|Supervisor||Ray Higginson (Supervisor), Joyce Kenkre (Supervisor) & Mark Williams (Supervisor)|