CST presentation Colin Nice Tim Hartshorne

AAA CST information and support day presentation

1. AAA CST Information & Support Day 27 April 2018 Colin Nice/Tim Hartshorne

2. Image Quality Accurate measurement of the abdominal aorta with ultrasound is a central activity of the National AAA screening programme; PS5 The percentage of assessed images of acceptable quality. PS6 The percentage inaccurate calliper placement determined by review of static images PS7 The percentage of screening encounters where aorta could not be visualised Pathway Standards for NHS Abdominal Aortic Aneurysm Screening Programme Version 1.3/ June 2016 Public Health England

3. BUT It is not currently possible to reliably assess compliance with standards 5and 6 for the following reasons; The characteristics of an acceptable image are not sufficiently defined The current terminology is subjective Programme quality assurance (QA) leads have a potential conflict of interest; There is no external quality assurance of image quality (the current system is reliant upon self-reported data) In current practice pathway standards 5 and 6 are seldom discussed.

4. Conflict of interest Declaring a high level of poor quality examinations will generate a high number of recalls which is unsatisfactory for the men concerned and to both the local and national programmes. This will place workload pressures on the programmes to perform these additional measurements without generating any additional income. Programmes will not wish to be identified as poorly performing

5. What isn’t adequately quality assured at present Image quality The image QA process

6. Short term working group Advice from DRS re consensus 5 workshops then National test exercise immediately afterwards 8 lead screeners 60 screeners Collected info regarding experience as a screener and qualifications Scottish National Image Quality Assessment Exercise in October 2017. Abdominal Aortic Aneurysm (AAA) National Image Quality Assessment Exercise Report to Lead Screeners Workforce Group NHS National Services Scotland Date: October 2017 Version: 1.5

7. Lead screeners submitted images

8. Image assessment Assessment criteria Calliper placement Image and measurement angle Image quality Gain Depth Focus Sector width Image size Anatomy (Consideration given to technical limitations provided it is apparent that every effort has been made to maximise the equipment) Findings Lead screeners 24/25 Consensus Screeners 14/24 Consensus

9. Recommendations Screener training IT National QA lead Possible limitation-(in my view) Images Very good quality but collected with specific outcomes in mind therefore do not cover all of the range. Tend to be either very good quality or a single clearcut abnormality/omission . Potential for large numbers of recalls

10. PHE Screening Image Quality Workshop 2017 To initiate project/working group to further develop, improve and update the mechanism and reporting for assessing quality of images undertaken by screening technicians within NAAASP Currently the image characteristics assessed at QA and recorded on the Screening Management and Referrals Tracking ( SMaRT ) IT system comprise; Depth Focus Gain Calliper placement Should we add anatomical landmarks? lumbar spine on both the longitudinal (LS) and transverse (TS) images and the inferior vena cava (IVC) on TS images

11. Image Quality Workshop 2017 It was also agreed that any scoring system should be; Simple Practical Able to achieve reproducible results Applicable to all AAA screening images These factors were collated into a 10 point scoring system

12. Benchmarking A small local benchmarking exercise (n=50) was conducted, with permission from the NHS AAA Screening Research Advisory Committee. Practical, a time penalty but this was relatively small and reduced as familiarity improved (a printed paper copy alongside a single screen PC set up was used). It was possible to apply a reasonable score to every examination. Scores achieved was 6-10 (with a mean of 7.28), low scores were infrequent so there would be a relatively narrow spread of scores. No penalty marks were awarded. No adjustment for case-mix but the system did not seem to penalise ‘difficult’ examinations . Issues to resolve, included images containing bowel gas, image centring, and thresholds for scoring image depth and calliper placement.

13. Survey of CSTs and QA leads with from the PHE Screening information and education for public and professionals (IEPP)

14. Activity

15. Depth

16. 5 Freetext answers ‘as close to 25% as possible but with visible landmarks’ ‘It will depend on the size of the man. If we are imaging at 15cm depth a 2cm aorta will only occupy 13% of the screen and be acceptable. If the quality of image is poor the aorta may need to be in the centre of the screen to be at optimal focal zone. If the image is clear I just want to see the spine at the bottom of the image and not a lot of wasted image below the spine’. 25-50% ‘The depth is optimised to demonstrate the spine is in the far field with the aorta anterior to it. (The % of the image occupied by the aorta is dependent on patient body mass index )’ ‘I like the depth adjusted so aorta uses as much of screen as possible whilst retaining spine as landmark. Depending on BMI this is a variable % of screen’

17. Calliper placement

18. Freetext answers ‘as small as possible and ensuring pathway is not compromised’ ‘> 5 degrees deviation from perpendicular to long axis of aorta’ ‘Depends on the clinical picture and whether it makes a difference to the patient clinical pathway’ ‘This is not a measuring parameter we use. Ideally the caliper placement should be perpendicular but to measure this to a 10/15 degrees would be very difficult’ ‘<10’

19. Anatomical Landmarks

20. Omissions/Penalties

21. Survey conclusions CST and QA leads are willing to help-THANK YOU Optimal depth-aorta occupies 15-25% ( of the vertical image distance on the best recorded longitudinal and transverse images ) Threshold between suboptimal and poor calliper placement >10 degrees deviation to long axis of aorta Essential landmarks Lumbar spine on longitudinal and transverse views and IVC on travsverse views Omissions or errors to be penalised? Callipers not placed inner to inner and wrong nhs no/demographics recorded

22. What happens now? NAAASP and local research applications submitted If approved we hope to recruit 20+ CSTs/QA leads Score an image set of 50 cases (anonymised) comparing (in 2hours) Scottish criteria Alternative 10 point scale Reliability Reproducibility Time efficiency and user comments For further information please contact [email protected] or [email protected]