Problem Representation

The problem representation is a succinct, processed summary of a patient’s story, that aids the clinician to summarise their thoughts and build a differential diagnosis. The "one liner" statement is used to summarise patient cases in notes and is the back bone of effective communication with other doctors.
The problem representation starts during the patient encounter as an internal, mental model for the patient’s main problem, and is refined throughout the encounter. It guides history-taking and the physical exam by defining the problem & sparking ideas about the differential or possible categories of disease. It helps identify important questions to ask or exam manoeuvres to do. 
When we sit down to write our note or give an oral presentation, we use the problem representation we’ve built in our minds as a starting point to craft the sentence that starts the initial 'one liner' summary statement, and this is the final problem representation. 
The problem representation is linked to the presenting complaint statement. The key differences are that the presenting complaint is much shorter, and it doesn't have details about the exam or test results, and is only focused on briefly describing the presenting symptom.
 What to include and exclude in a problem representation
Who is the patient?
- Relevant demographics and risk factors
What is the temporal pattern of illness? 
- Length (hyperacute, acute, subacute, chronic)
- Tempo (stable, progressive, resolving, intermittent, waxing and waning)
What is the clinical syndrome?
- Key/differentiating features of the clinical syndrome (signs/symptoms)
- Using IASP taxonomy where relevant (e.g. lumbar spinal pain not low back pain)
It excludes irrelevant information. A patient’s inguinal hernia is likely irrelevant to their neck pain. It also excludes Non-specific information. Fatigue rarely helps to narrow our differential diagnosis
The problem representation activates illness scripts within the doctor's memory. Illness scripts are mental representations of potential diagnoses. The clinician uses a comparison process. In this process they generate a prioritised differential diagnosis which is based on how closely the patients problem representation compares to previous illness scripts (or disease prototypes)
The problem representation has many advantages to both experienced clinicians and learners alike
* To use pattern recognition to quickly develop a differential diagnosis. 
* Translates lay language into medical terminology, allowing easier access to the clinician's internally stored illness scripts. 
* Reduces cognitive load and facilitates problem-solving by summarising the most salient features and minimising distractors.
* Allows learners to develop their reasoning skills - e.g. what is most relevant to a given clinical problem? How do we specifically define a clinical problem in order to begin to solve it? 
Example
Consider the following case.
A 60-year-old woman presents with two months history of bilateral shoulder pain, morning stiffness, and malaise. She is previously healthy other than a history of ORIF for a fibula fracture. On examination she has proximal muscle weakness and globally restricted shoulder range of motion. Blood work is significant for a CRP of 15 and ESR of 32. 
* A concise problem representation: A 60-year-old previously healthy woman presents with subacute inflammatory proximal limb pain and weakness.
* A less succinct problem representation: A 60-year-old woman presents with two months of bilateral shoulder pain and weakness in the setting of malaise and morning stiffness, with an exam significant for restricted shoulder range of motion, and an elevated CRP and ESR.
The model problem representation is ideal because it succinctly answers the three key questions in the table above. Who is the patient, What is the temporal pattern of illness, and What is the clinical syndrome. 
* A 60-year-old previously healthy woman - who is the patient
* presents with subacute - what is the temporal pattern of illness
* inflammatory proximal limb pain and weakness - what is the clinical syndrome
Note how in the model problem representation elevated CRP and ESR becomes "inflammatory," nonspecific information (e.g. malaise) is excluded, and two months becomes "subacute"
==Resources==
*JGIM Problem Representation Overview
== References ==
Category:Clinical Reasoning