Substitution/ Supplementation in ACP

A major feature I found in my systematic literature review regarding the benefits of Advanced Clinical Practice related to whether the definition, nomenclature, and scope of the ACP role is a substitution or a supplementation.

This is where ACPs are either employed to take on the work normally or previously performed by others (e.g. junior doctors) thus “freeing them up to concentrate on other elements of care” (McDonnell et al., 2014, p. 794), or if they hold their own case load within a service which may previously have not existed or was fragmented across a number of services or role holders (e.g. outreach or care co-ordinators). This can be categorised as role extension (substitution) or role expansion (supplementation).

Substitution/ supplementation is a common feature in terms of the impetus for development and thereby the definition and scope that is afforded to ACPs. Several authors noted that a main driver for development of ACP roles has been due to a shortage of doctors or where policy change, such as the imposition of a restriction on junior doctors hours, or a requirement to reduce waiting lists has affected the supply of medical professionals. 

A significant number of ACP roles, at least in their development and early stages of implementation, have been aimed at substitution.  However, there is evidence that whilst the impetus may have been to address the shortage of doctors, there had actually been no reduction in the number of medical posts. This may be due to increasing demands on the service, but also the reluctance of medical staff to accept ACPs had the skills to cover them, (a commonly identified barrier to ACP).

There is also evidence that whilst substitution often has provided an impetus for creating ACP roles, once in place ACPs are then well positioned to develop supplementary or ‘added value’ services and drive the evolution of these roles. These new services are aimed at promoting high quality care or responding to changing demands on health care systems, and filling gaps in services that need addressing. This could be described as a type of re-engineering that shifts the focus to patient centred rather than profession centered services and care, using case management and multi-disciplinary approaches.

Delamaire and Lafortune (2010) draw attention to hierarchical and non-hierarchical forms of ACP where the degrees to which ACPs are substituting and are supervised by doctors may have an impact on the extent they are able to operate as autonomous practitioners. The extent of autonomy further influences how much ACPs draw, to a lesser or greater extent, on their own professional background, theoretical frameworks, knowledge and skills rather than purely using the ‘medical model’. This has an impact on whether re-engineering of services which involves innovative ideas about changing professional roles and shifts the focus to patient centred care can take place. The evidence from my literature review demonstrated that where substitution is in place this can lead to fragmentation of care , lack of clarity and autonomy in roles and lines of responsibility, and can trigger others feeling disempowered or may risk the loss of skills of those substituted over time.

An example of this is my experience of when Critical Care Outreach roles were first implemented. A key aspect to the success of their role was to upskill and support ward based staff. They were not there just to swoop in when a patient is deteriorating to provide medical interventions and swoop out again when they are stable without providing safety netting, advice, training, and support to staff close to the patient to continue their care and avoid further episodes of deterioration, (as perhaps had happened previously when relying purely on resuscitation teams to deal with potentially terminal crisis events). This led to the concept of ‘Critical Care Without Walls’ where advanced practitioners were specifically employed to bridge the gap between the geographic location of the patient and the critical care unit to provide coordination and continuity of care for the deteriorating and recovering critically ill patient.

This brings us back to the topic of localisation in ACP and how the local relationships, practice, attitudes, and policies plays a crucial role of reallocation of tasks (i.e. in substitution roles). Case studies and narratives from ACPs experiences reveal that “legally assigned clinical activities sometimes cannot be carried out due to restrictive local arrangements” and this can lead to ACPs not being able to practice their full scope of competence (De Bont et al., 2016, p. 8).  This view is supported by a number of authors in noting that where ACPs were bought in to ‘fill gaps’ their scope of practice becomes limited to clinical tasks.  This can impact on costs, and the measurable outcomes achieved by ACPs.

Delamaire and Lafortune (2010) note that where the ACP role is used as a substitution for others, it has been shown to be equivalent to or produce a reduction in costs (although commonly the full costs have not been included such as costs of education). Where ACPs are used to provide a supplementary or ‘adding value’ service, costs are shown to increase, (but again commonly the long-term costs have not been fully evaluated such as effects on preventing future hospitalisation or enhancing continuity of care).  

However, this broad assumption relies on a number of factors which may tip the scale of cost evaluation either way. For example, ACPs may be paid less than doctors (depending on their grade) but may also provide an enhanced or ‘added value’ service which allows them to spend a greater amount of time with patients. This may still require some supervision from doctors for this ‘added value service’ and, over time, may cost the equivalent or more than the ‘standard’, time-restricted, service that would have been delivered if ACPs had not replaced doctors in this part of the clinical pathway. This, combined with variety of education routes (and thereby costs to supply training and education to ACPs) makes drawing any broad conclusions about cost of ACP in the UK difficult.

It would of course be perverse to want cost reduction to be the only or primary outcome measure in healthcare, where positive clinical outcomes are the more desirable, standard, and required outcome measure that is expected.

From the evaluation of literature, it can be argued that substitution roles are not well placed to facilitate the full remit of ACP and to maximise the benefit that can be gained from effective employment of these roles which requires that this includes, but also goes beyond, operation of clinical tasks. We may need to accept that substitution has often been a starting point, but supplementation and adding value should always be the goal. If this can be baked in from the beginning of ACP role development the opportunity to “harness the brilliance” of ACPs can be achieved. [Quote from Deborah Harding at the 2022 Centre for Advancing Practice ‘Empowering People, Transforming Care’ conference].


De Bont, A., Van Exel, J., Coretti, S., Güldem Ökem, Z., Janssen, M., Lofthus Hope, K., Ludwicki, T., Zander, B., Zvonickova, M., Bond, C. and Wallenburg, I. (2016) ‘Reconfiguring health workforce: a case-based comparative study explaining the increasingly diverse professional roles in Europe’, 16, pp. 1-14.

Delamaire, M.-L. and Lafortune, G. (2010) ‘Nurses in Advanced Roles: A Description and Evaluation of Experiences in 12 Developed Countries’.

McDonnell, A., Goodwin, E., Kennedy, F., Hawley, K., Gerrish, K., Smith, C. and (2014) ‘An evaluation of the implementation of Advanced Nurse Practitioner (ANP) roles in an acute hospital setting’, 71, pp. 789-799.

Published by vjscottcpd

Vikki-Jo was Head and then Dean of School for Health & Social Care (formerly Health & Human Sciences) since 2013 until 2019. She is a registered Nurse with a background in Critical Care Nursing. Since working in academia she has focused on Continuing Professional Development for Health and Social Care professionals. She is a Senior Fellow of the Higher Education Academy with a Masters in Learning and Teaching. In 2020 she commenced her PhD focussing on Advanced Clinical practice education. At this time she also returned to working in Critical Care during the Covid-19 pandemic.

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