The Use of the Ankle Brachial Pressure Index (ABPI) in General Practice

Background

What is Peripheral Arterial Disease (PAD)?

• 6x risk CVS morbidity and mortality
• 202 million globally
• Developed and Developing countries
• 12-14% gen population
• Higher in >60yrs
• $26million 2011-12 in NZ
• Increasing prevalence!!
• But preventable.

The Use of the

Ankle Brachial Pressure Index (ABPI) in General Practice

“the most cost-effective tool for lower extremity PAD detection is the ABPI”

“the ABPI has been validated against lower extremity contrast angiography to determine its sensitivity, specificity , and accuracy as a lower extremity PAD diagnostic tool"

Acknowledgements

Professor Susan Dovey

Dr Hywel Lloyd

Department of General Practice and Rural Health, University of Otago

BPAC Scholarship

Maurice and Phyllis Paykel Research Trust Award in Medical Sciences

Thomas Ding

BMedSc (hons) Candidate

Department of General Practice and Rural Health, University of Otago

2015

What are ABPIs?

Literature regarding ABPIs in general practice

• Limited
• No New Zealand data
• Additional benefits of its use in General Practice:
• Aids appropriate referrals -> 41% IC inappropriate
• Ease of use, objective -> 9% intra-observer variability
• Patient-centred multidisciplinary care
• YET no real world follow-up data

References

Simple to use

Cost-effective

Relatively quick

Reliable

Non-invasive

• Fowkes FG, Rudan D, Rudan I, Aboyans V, Denenberg JO, McDermott MM, et al. Comparison of global estimates of prevalence and risk factors for peripheral artery disease in 2000 and 2010: a systematic review and analysis. Lancet. 2013;382(9901):1329-1340.
• Al-Qaisi M, Nott DM, King DH, Kaddoura S. Ankle brachial pressure index (ABPI): An update for practitioners. Vasc Health Risk Manag. 2009;5:833-841.
• Hirsch AT, Duval S. The global pandemic of peripheral artery disease. The Lancet. 2013;382(9901):1312-1314.
• Diehm C, Allenberg JR, Pittrow D, Mahn M, Tepohl G, Haberl RL, et al. Mortality and vascular morbidity in older adults with asymptomatic versus symptomatic peripheral artery disease. Circulation. 2009;120(21):2053-2061.
• Hirsch AT, Haskal ZJ, Hertzer NR, Bakal CW, Creager MA, Halperin JL, et al. ACC/AHA 2005 Practice Guidelines for the management of patients with peripheral arterial disease (lower extremity, renal, mesenteric, and abdominal aortic): a collaborative report from the American Association for Vascular Surgery/Society for Vascular Surgery, Society for Cardiovascular Angiography and Interventions, Society for Vascular Medicine and Biology, Society of Interventional Radiology, and the ACC/AHA Task Force on Practice Guidelines (Writing Committee to Develop Guidelines for the Management of Patients With Peripheral Arterial Disease): endorsed by the American Association of Cardiovascular and Pulmonary Rehabilitation; National Heart, Lung, and Blood Institute; Society for Vascular Nursing; TransAtlantic Inter-Society Consensus; and Vascular Disease Foundation. Circulation. 2006;113(11):e463-654.
• Ferreira AC, Macedo FY. A review of simple, non-invasive means of assessing peripheral arterial disease and implications for medical management. Ann Med. 2010;42(2):139-150.
• BPAC. Ankle-brachial Pressure index: an under-used tool in primary care? 2014.

So... What is the usefulness of the ABPI in general practice?

The Use of the ABPI in General Practice- A Mixed Methods Study

• Quantitative analysis of ABPI patients at Mosgiel Health Centre (MHC) between 2006-2015
• Qualitative analysis of health professionals' views towards ABPI in general practice

Quantitative Arm- The Use of the ABPI in a General Practice over Ten Years

Methods

Qualitative Arm- Interviewing Local Health Professionals regarding the ABPI in Primary Care

• Semi-structured one-to-one interviews
• Snowball sampling
• Transcription & Coding
• External analyst
• Mapping & Themes

Aims

• To describe who is receiving ABPI investigations at MHC between 2006-2015.
• To describe why and how the ABPI are being used in the MHC.
• To analyse whether ABPI use is associated with a change in clinical management (compared to what would have been done without ABPI).
• To interpret the significance and effectiveness of conducting the ABPI.

Other thoughts

• 3-4 done per month (with referrals)- is this enough?

Aims

• To explore perspectives of health professionals on the ABPI
• To understand the prior knowledge and prior experience had
• To understand the perceived advantages of using the ABPI in general practice.
• To gain understanding around challenges which hinder or prevent the use of the ABPI in general practice.

Results- Demographics

Results- Advantages

• Who?
• 2/9 did ABPIs regularly

Results- Previous Experience

• Diagnose PAD
• Check for mixed disease
• Aids referrals being accepted
• ….
• Decrease the burden on secondary care
• Triaging in secondary care
• Ability to manage patients to a greater extent in primary care
• Ease of use
• An aid in conveying cardiovascular risk

7/9 previous experience of sorts

4/9 medical school

3/9 house officer

Those who did do ABPIs regularly had experience

No formal experience

Results- Disadvantages

• Taking too much time
• Being too costly- equipment, human resources
• Having a low patient need for ABPIs
• ….
• Lack of awareness of the ABPI’s value
• Lacking confidence in ability
• Test results not changing management
• Not a priority for primary care
• Having enough physical space

Key Findings

Methods

• Anonymised electronic patient data & secured database
• Extraction and Collection of data for all ABPIs/patients 2006-2015
• ABPIs completed by Dr Hywel Lloyd following NZGG guidelines

• Indications:Over half were used to guide management of a venous-related issue, with just under half completed to investigate suspected PAD.

• 24.5% of right-sided and 21.6% of left-sided ABPIs were <0.9, indicating PAD or mixed disease

• 23.2% reassured, 17.7% additional management for differentials

• 100 (26.39%) patients were referred to the vascular department. This means 73.61% of patients having ABPIs were not referred, and suggests that this is the proportion of inappropriate referrals saved by doing ABPIs.

Thoughts on both arms

Results- Outcomes

Results- Is there a role? Whose role?

• Results

• GPs themselves?
• Nursing colleagues?
• Specialised tool for GPSIs/Specialist practitioners?
• One professional?
• Not primary care’s responsibility?

• ABPI is a well-established recommended tool for objective use of diagnosing and quantifying PAD
• There is follow-up evidence at MHC to support its use, namely in aiding diagnosis, management and appropriate referral
• GPs acknowledge the benefits but note practical barriers preventing current use and low need
• Thinking around restructuring the way ABPIs are performed in general practice e.g. GPSI for a community such as Mosgiel
• Further research to compare ABPI use in other practices and interviewing a broader range of professionals- rural, nursing, other cities
• Short term implications- resources at MHC, reminding practitioners about ABPI

Results- Indications

Results

Demographics (vs total MHC population)

• Female 64% (52%)
• Older
• Ethnicity proportions similar except NZ Māori 1.65% (5%)
• Socio-economic- larger more-deprived 30% (20%) and smaller least-deprived 19% (34%)
• Over-represented in atherosclerotic disease, venous disease, edema, DM, ulcers, CHF, gout, HLD, HTN

design by Dóri Sirály for Prezi