Why community pharmacists need skills in differential diagnosis

By 2026 all pharmacy graduates will have an independent prescribing qualification and there will be a increasing emphasis on clinical activities in community pharmacy.  Professor Rutter’s new book uses a case-study format and emphasises the importance of clinical reasoning to reach a diagnosis.

The WWHAM mnemonic is no longer adequate to guide consultations, he explains.

WWHAM stands for:

• Who: Who is the medicine for?
• What: What are the symptoms?
• How long: How long have the symptoms been present?
• Action: What action has been taken?
• Medication: Are you taking any other medication?

How clinical reasoning underpins effective consultations

Professor Rutter’s new book follows a case study format because this is an effective way to “contextualise facts and figures and knowledge into something more ‘real life’”, he says. For example, a symptom such as cough would be approached very differently in a 75-year-old man from a 5-year-old child. The objective of the consultation is to sift out from the list of possible causes of cough those that are most likely in the patient in question. Clinical reasoning is flexible and responsive and allows the practitioner to take a long list of conditions and narrow it down into a smaller number of possibilities in a logical way.

Clinical reasoning – the challenge of moving from novice to expert

The Pharmacy First scheme allows the pharmacist access to medicines which otherwise would be prescription only medicines (POMs), in specific situations. Clinical reasoning is important in establishing a diagnosis which is the first step in the Pharmacy First service.  Professor Rutter envisages that the Pharmacy First service will be extended in future as part of the movement to make pharmacy a more clinical profession. This will call for more expertise in clinical reasoning and feedback on pharmacists’ performance will be essential to raise their “ceiling of competence”, he explains.

In future, community pharmacists’ clinical role will be extended further and the traditional dispensing role will diminish. In addition, “I think the digital side of pharmacy will increase and that will hopefully allow greater communication between pharmacy and general practice services so they’re better integrated”, he says.

About Paul Rutter

Paul Rutter is  Professor of Pharmacy Practice at Portsmouth University. His main area of interest is differential diagnosis of minor conditions for pharmacists and his academic teaching deals mainly with this topic. He is the author of the textbook, Symptoms, Diagnosis and Treatment in Community Pharmacy, now in its fifth edition. His new book, Differential diagnosis for non-medical prescribers, nurses and pharmacists: A case-based approach, was published in August 2024.

Read and watch the full series on our website or on YouTube.

Link to Pharmacy First 

The Pharmacy First scheme allows the pharmacist access to medicines which otherwise would be prescription only medicines (POMs), in specific situations. This is expected to relieve some pressure on GP services. However, “You’ve still got to make that diagnosis, you’ve still got to get to the point that you are confident that you are dealing with condition X and then you can use the Pharmacy First service to supply the appropriate medicine”, says Professor Rutter. The pharmacist is still responsible for making the diagnosis and the new book “will  help pharmacists establish the diagnosis with more confidence and more accuracy”, he adds.

Clinical Reasoning and Artificial Intelligence

Clinical reasoning and decision making is now creeping in to the undergraduate pharmacy curriculum as independent prescribing is becoming embedded. It is already a feature of post-graduate independent prescribing courses.

In future, artificial intelligence (AI) will undoubtedly play a role in teaching and delivery of services but is unlikely to take over clinical reasoning activities, says Professor Rutter. “Clinical reasoning is fundamentally a thinking and cognitive process that you have to do yourself. So, I think AI will be used to create test cases to give students opportunities to practice this clinical reasoning in a safe environment where they can build up their experience. I think it will augment and supplement how we teach clinical reasoning but the actual process of how you do clinical reasoning has still got to be thought through by the student themselves – so I don’t think AI will ever replace that”, he explains.

Clinical reasoning: from novice to expert

Professor Rutter envisages that the Pharmacy First service will be extended as part of the movement to make pharmacy a more clinical profession. Inevitably, the ways in which pharmacists arrive at a differential diagnosis will come under scrutiny, particularly from GPs who will have been taught clinical reasoning as part of the way they make a diagnosis. When they see that pharmacists are approaching the activity in the same way that they themselves would, it should give pharmacists more credibility and enable GPs to have more confidence in what they do, he says.

Clinical reasoning is, in some ways, a new activity for community pharmacists and it will take time for them to become experts. The development of expertise depends on experience – the more cases of a similar condition that a practitioner sees, the more his or her understanding of the way the condition presents develops. “The biggest challenge for pharmacists is how do you get that feedback …  to know you’re doing a good job”, says Professor Rutter.  If the diagnosis is uncertain then, as a community pharmacist , he would refer the patient to the GP but then rarely receives any feedback. “Most times in community pharmacy you don’t get feedback from the patient or the doctor to tell you whether you were right or wrong. Now for us to become good at clinical reasoning and more expert that loop needs to be closed. I think it’s important that pharmacists try to talk to their GPs when they’re making these referrals to say, “Well, I’m referring this case to you because I think it might be this but I’m not sure. I’d really appreciate it if you could tell me what you think so that I can improve for next time”, and by doing that you’re able to raise your ceiling of competence. …. [If] you get feedback on cases, over time your ceiling of competence goes up and up and up and you’re able to treat more and more patients”, he explains.

Vision for the future

In 10 years’ time, Professor Rutter foresees that community pharmacists’ clinical role will be extended further and most pharmacists will be independent prescribers. Dispensing in community pharmacies will be limited to items required immediately  and much will be done remotely with medicines delivered by post. Pharmacists will the be free to concentrate their efforts on management of long-term conditions for stable patients. “Many of the roles that GPs currently perform I think will be performed in a pharmacy and patients will be directed to the pharmacy more and more rather than the GP. So, I only see the clinical side of pharmacy growing and the traditional kind of dispensing side of pharmacy disappearing. I think we will, at that point, in 10 years’ time, be a very clinical, patient-facing profession. I think the digital side of pharmacy will increase and that will hopefully allow greater communication between pharmacy and general practice services so they’re better integrated”, he says.

About Paul Rutter

Paul Rutter is  Professor of Pharmacy Practice at Portsmouth University. His main area of interest is differential diagnosis of minor conditions for pharmacists and his academic teaching deals mainly with this topic. He is the author of the textbook, Symptoms, Diagnosis and Treatment in Community Pharmacy, now in its fifth edition. His new book, Differential diagnosis for non-medical prescribers, nurses and pharmacists: A case-based approach, was published in August 2024.

Read and watch the full series on our website or on YouTube.

Professor Rutter’s new book follows a case study format because this is an effective way to “contextualise facts and figures and knowledge into something more ‘real life’”, he says. For example, a symptom such as cough would be approached very differently in a 75-year-old man from a 5-year-old child.

Clinical reasoning plays a critical role here. “It’s about bringing forward to the conscious level your thinking. So, it’s about testing a hypothesis,  it’s about thinking “Well, if I’ve got a 5-year-old child with a cough, what’s the likely diagnosis?” and then testing that hypothesis by asking those questions which are pertinent at that time in the conversation. And the type of question will change depending on the context and it will depend on the response of the patient as to what question you would then ask next”, he explains.  “Clinical reasoning is very flexible it responds to what the patient says and you as the clinician are directed to ask your next question based on the information that’s been provided by the patient”, he adds. Each clinician might use a different series of questions for a given problem, depending on their experiences and the way in which they process the information from the patient, but should arrive at the same endpoint.

Returning to the examples above – a 5-year-old child who’s had a cough for a couple of weeks and a 75-year- old man who’s had a cough for three weeks – would call for slightly different questions. Whereas asking about the number of cigarettes smoked daily might be routine for an adult, it would not be appropriate for a 5-year-old child. The objective of the consultation is to sift out from the list of possible causes of cough those that are most likely in the patient in question. Clinical reasoning “allows you to take that long list of conditions and narrow it down into a smaller number of possible conditions which you then can test as to what is it likely to be. So, you might have 20 conditions which cause cough but straight away by the person that you’re talking to and the context that they present in – i.e. how long they’ve had it or things like that – you can go down from say 20 conditions to two or three or four quite quickly, but then you’re very targeted in the questions that you ask”, says Professor Rutter.

About Paul Rutter

Paul Rutter is  Professor of Pharmacy Practice at Portsmouth University. His main area of interest is differential diagnosis of minor conditions for pharmacists and his academic teaching deals mainly with this topic. He is the author of the textbook, Symptoms, Diagnosis and Treatment in Community Pharmacy, now in its fifth edition. His new book, Differential diagnosis for non-medical prescribers, nurses and pharmacists: A case-based approach, was published in August 2024.

Read and watch the full series on our website or on YouTube.

Professor Rutter’s main area of interest is differential diagnosis of minor conditions for pharmacists. His own career started in community pharmacy where he says he “really enjoyed interacting with patients”. He became a teacher/practitioner with Boots the Chemist and found that he also enjoyed teaching. He gained a PhD and started his academic career at Portsmouth University. After spells at Wolverhampton University and the University of Central Lancashire he returned to Portsmouth to take up the post of Professor of  Pharmacy Practice.

Professor Rutter is probably best known for his book on symptoms diagnosis and treatment in Community Pharmacy, now in its fifth edition. His new book, Differential diagnosis for non-medical prescribers, nurses and pharmacists: A case-based approach, is intended to fill a gap that is not covered by the earlier book.  As the scope of practice for community pharmacists expands, skills in differential diagnosis of signs and symptoms will become increasingly important, he says. “We all know that we’re going to have a prescribing workforce – by 2026 all [pharmacy] graduates will have that IP (independent prescribing) qualification and this book is trying to address that extended role for pharmacy”, he explains. The book uses a case-study format and emphasises the importance of clinical reasoning to reach a diagnosis.

Hitherto, pharmacists have relied on the WWHAM (or 2-WHAM) mnemonic to guide consultations. WWHAM stands for:

• Who: Who is the medicine for?
• What: What are the symptoms?
• How long: How long have the symptoms been present?
• Action: What action has been taken?
• Medication: Are you taking any other medication?

Although WWHAM elicits some information from patients it is not a good diagnostic tool. “If you think about the questions that it asks, at least two of those five questions are more to do with management and treatment planning rather than the diagnosis so it doesn’t actually ask many questions to establish the differential diagnosis”, says Professor Rutter. The role of pharmacy in the community has now developed further. “Because we are now being expected to do a lot more in pharmacy, we need to adopt new ways of thinking and new ways of getting information from the patient – and that’s where clinical reasoning comes in”, he explains. The new book is focused on the use of clinical reasoning in order to establish a differential diagnosis, he adds.

WWHAM still has a  place – ideally it is a tool that should be used by pharmacy counter assistants to obtain basic information that can be given to a  pharmacist prior to a consultation, says Professor Rutter.

About Paul Rutter

Paul Rutter is  Professor of Pharmacy Practice at Portsmouth University. His main area of interest is differential diagnosis of minor conditions for pharmacists and his academic teaching deals mainly with this topic. He is the author of the textbook, Symptoms, Diagnosis and Treatment in Community Pharmacy, now in its fifth edition. His new book, Differential diagnosis for non-medical prescribers, nurses and pharmacists: A case-based approach, was published in August 2024.

Read and watch the full series on our website or on YouTube.