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Why do we prescribe what we prescribe?

In this video, David Tisdall discusses the factors involved in our antibiotic prescribing decisions.
In this session, I want us to explore together the motivations that underpin our prescribing decisions. Really to answer the question, why do we prescribe what we prescribe? And right at the start, I’d just like us to take a moment to pause and reflect together, perhaps stop the video for a couple of minutes and write down your responses to this question. What questions do you ask yourself before deciding to prescribe an antibiotic?
Now, it is clear that prescribing antibiotics is a common outcome of veterinary consultations. I could have picked an example from across the species disciplines to illustrate this, but actually, I think this publication in the vet record from 2011 based on data from the small animal veterinary surveillance network, or SAVSNET, is actually really helpful in illustrating this for us. And one of the key findings that in this study was that prescribing antibiotics was a feature of between 35% and nearly 50% of consultations. So I think we can all agree that antimicrobial prescribing is a common habit that we all share as veterinary practitioners. The real question is, what are the motivations that underpin those prescribing decisions?
And as you might imagine, it’s complex, and it is made up of a range of extrinsic and intrinsic factors that we’re going to explore in turn. So we’ll start thinking about some of the extrinsic factors that influence our prescribing decisions. Perhaps those in the green box there are the most obvious. Those are all the factors that directly pertain to the case, so things like the clinical findings and particular factors to do with the patients. Things related to the medications themselves, so licencing, and if you’re working within the UK, the prescribing cascades. It’s also important to consider, if you’re working in food animal practice, withhold times for different medications. That might influence our prescribing decisions.
But that’s only a small part of the picture, and actually, some of the evidence that we’re going to talk about really suggests that some of those factors that are included in the orange box above actually have a bigger impact, a bigger pool than those related to the case of the medication we’re using. So the culture in the practice is really important in setting patterns of prescribing, particularly to do with the leadership that’s provided by senior veterinary practitioners. Client expectations.
I guess in the sense of perhaps perceived pressure on vets to prescribe because they suspect that that’s the outcome that their clients want, and perhaps there is some sense of reputational risks that vets might feel that if they choose not to prescribe, that has a risk perhaps to their business.
Then there’s some very practical concerns. So something that comes out of the literature as well is that time pressure on veterinary consultations means that sometimes prescribing an antibiotic is actually just the easier option, rather than really getting to the bottom of what’s going on with the case, perhaps through further diagnostic testing or changing the management of that animal or exploring other treatment options. And then there’s the economic aspects of this case. We cannot ignore the fact that vets– veterinary businesses– rely to some extent for our income on medicine sales. And so sometimes that could have an influence on our prescribing decisions.
Those are all things from outside of ourselves that have a bearing, but that’s definitely not the full picture, because there’s a whole range of intrinsic factors that influence our prescribing decisions as well, and a lot of these have to do with our own personal confidence and attitude to risk. Clinical experience helps to some extent with this, familiarity with the case presentation is likely to give you more confidence in the decisions that you’re making, and particularly, the decision not to prescribe. Often, prescribing can be driven to some extent by a sense of discomfort that we have with uncertainty surrounding case management.
Often, we really don’t know what is going on, and so we’re trying to treat the most likely cause in the majority of cases, and some of us feel more comfortable with that uncertainty than others. Quite early on in our careers, we tend to develop our own habits of prescribing, our own patterns of medicines use, which actually become established and quite difficult to break. And ultimately, the decisions to prescribe and the relative importance we place perhaps on antimicrobial stewardship and on addressing antimicrobial resistance are quite deeply ingrained and related to our own values and belief system.
So actually, the decision to prescribe is complex, and we need to acknowledge that there are all these different extrinsic and intrinsic factors that are at play. We need to be wise to them so that we can make sure that we are allowing those factors that really should influence our prescribing decisions to hold the greatest weight. It’s unsurprising that this full range of behavioural drivers and barriers to antimicrobial stewardship are brought out in the literature, and this recent paper in the veterinary record is a good example.
This identified that the two areas that were perhaps of greatest opportunity to target for improving antimicrobial stewardship and veterinary practice based on expert consensus related to the antimicrobial prescribing behaviour of vets, and addressing inappropriate, unnecessary, or defensive prescribing, and also to issues relating to interactions with the clients. So perhaps their expectation and perceived pressure on the vets to prescribe, or the fact that as we’ve already considered, there is often insufficient time to have the in-depth conversations that are really necessary in a typical consultation. Practice culture, infection control practises, and the use of diagnostic tests were all other potential drivers that could support antimicrobial stewardship going forwards.
But it’s interesting that those at the top of the list were the antimicrobial prescribing of the vets, their habit, their tendency to prescribe, and the interactions between the vets and the clients. And all these factors– all these different examples that I’ve talked about can drive what’s known as defensive prescribing or that tendency, as it were, to give antimicrobials just in case, and what this term really reflects is the reality that, in practice, often, we’re only treating what we consider to be the most likely cause. We don’t really know the exact bacteria that might be there in a particular case.
We definitely don’t know when we’re making an empirical prescribing decision, and that uncertainty creates a degree of discomfort, which can drive us towards prescribing. And when you couple that with the fact that we’re invested in a good outcome for our clients and a good outcome for their pets or for their farm animal, that can put quite a lot of pressure to prescribe, to perhaps cover ourselves, and to cover the patients, because we don’t want to risk a bad outcome by not prescribing, even if the lower outcome likelihood of that is relatively low. And this uncertainty relates to diagnostics– diagnosis and prognosis. The likely presence of AMR.
Ideas around how likely our treatment is to be effective and recovery time and client expectations. But really, it’s to do with how we manage internal– these internal and external pressures. Those intrinsic and extrinsic factors that we talked about earlier, and one of the ways to help us avoid defensive prescribing is to be aware that there are all those different factors at play when we come to make a prescribing decision.
In this video, David Tisdall discusses the factors involved in our prescribing decisions.
There are several extrinsic and intrinsic factors that are considered.
Some examples of intrinsic and extrinsic factors influencing prescribing Click to enlarge
Often it is these intrinsic factors, alongside the practice culture and client expectations, that can have a biggest influence on prescribing decisions. A tendency towards defensive prescribing is common. This is also the same in human medicine. For example, this study, found that individual GP prescribing behaviour had a greater influence on AM prescription than the clinical picture.
Another study, in a hospital scenario, looked at compliance of physicians with antimicrobial guidelines. It found that patient characteristics had limited effect on compliance. There was a tendency towards defensive prescribing and the use of more broad-spectrum antibiotics, particularly with severe infections, without de-escalation following culture and sensitivity testing. The authors of this study suggested that clinicians may have been prioritising perceived treatment efficiency and efficacy in individual cases, over the bigger picture of reducing AMR risk.

In summary:

Professor Dame Sally Macintyre, University of Glasgow, said
“The mechanisms which lead to antimicrobial resistance are biological. However, the conditions promoting, or mitigating against, these biological mechanisms are profoundly social.”
Antimicrobial stewardship is fundamentally an issue of behavioural change.
For more information on behavioural change and methods of implementing change into practices, take a look at this course: Tackling Antimicrobial Resistance: A Social Science Approach.
In the comments section below, discuss your answers to the question David posed at the start of the video: what questions do you ask yourself before deciding to prescribe an antibiotic?
Do you think you tend to defensively prescribe? When and why are most likely to do so?
How could you change the questions that you ask yourself, so that defensive prescribing is avoided?
In the see also section, an article has been provided for further reading.
Please find a downloadable copy of the PowerPoint slides used in the video in the downloads section below.
This article is from the free online

Antimicrobial Stewardship in Veterinary Practice

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