The results show that there is no statistically significant difference between the ability of student podiatrists and HCPC registered podiatrists to identify correctly Doppler ultrasound sound recordings of the blood flow in the posterior tibial artery. Furthermore, both groups showed mean correct identification rates of better than 12 out of 15, suggesting reasonable identification abilities. This is somewhat contrary to the findings of similar studies [13, 15, 16]. These all showed qualified professionals produced better results than less experienced healthcare workers during different vascular assessment skills.
In view of the potential, or even expectation, for the enhancement of diagnostic skills, such as the use of Doppler ultrasound, through a combination of mandatory CPD and clinical experience, the results of this study raise an interesting question. Why were the practitioners not better than the students? The disagreement with the findings with those of previous studies [13, 15, 16] with regard to the lack of difference in performance between qualified professionals and less experienced healthcare workers, could be the result of a number of factors. The registered participants were drawn from a professional body local branch meeting and all were HCPC registered. However, not all had qualified in podiatry through the three/four year diploma or degree route, and there was therefore no guarantee that each practitioner had received training in the use of a Doppler machine. The sample of registered participants included both NHS based and private practice based practitioners. There was therefore a variation in access to training and equipment, and in the frequency with which Doppler ultrasound was used as a standard assessment tool. A number of private practice based practitioners either did not possess, or rarely used a Doppler ultrasound hand held machine for screening purposes. While the practitioner sample showed variation in the frequency of use of Doppler ultrasound, the student sample did not, students using Doppler ultrasound as an assessment tool regularly and frequently. The use of student podiatrists rather than other less experienced healthcare workers could also therefore have contributed to the discord with previous findings. In view of the findings of this study, further research should be undertaken to investigate the differences in Doppler ultrasound interpretation by practitioners at different stages of their career, taking into account variations in training and CPD.
Patterns of correct identification for the three types of blood flow were seen to be the same for both groups, with monophasic sounds being most reliably identified, and triphasic the least reliably identified by both groups. These findings are contrary to those of previous studies by Vowden et al.  and Lithgoe and Barlow , who found biphasic pulses to be the most inconsistently interpreted sounds.
Some practitioners expressed concern about their own competence in the use of Doppler ultrasound and the interpretation of the sounds produced, citing a lack of knowledge, training and/or experience as reasons. All practitioners were recruited through attendance at the local Society branch meeting, and were therefore engaged in continuing professional development. Nevertheless, this raises concern over the competence of some practitioners to screen for PAD, and their role as holistic care practitioners . With increasing prevalence of high risk conditions such as peripheral vascular disease and type 2 diabetes, the results of this study identify a particular learning need within the podiatry community. Continuing professional development is mandatory under the Health and Care Professions Council Code of Conduct, and this study provides evidence of a need to offer support and education to practitioners who have rarely used, or have never been trained to use, a hand held Doppler ultrasound machine.
The study design minimised the number of uncontrolled variables. By using the same consulting room, headphones and computer software to play the Doppler audio sounds, every participant was exposed to the same environmental conditions, sound quality and recording order. However, the participants were taken out of their natural clinical setting and the test performed was in isolation of other information usually available to the podiatrist regarding the vascular status of the patient.