Problem Representation - Exercises in Clinical Reasoning

Introduction

The problem representation is a one-sentence summary that highlights the defining features of a case. It helps clinicians summarize their thoughts and then generate a differential diagnosis. The “one-liner” statements used to summarize patient cases on rounds, in notes, or when calling consults are all versions of the problem representation. A problem representation should be updated iteratively as the clinician gathers data throughout a patient encounter. A well-formed problem representation facilitates clinical reasoning and serves as the backbone for how clinicians communicate with one another.

The Problem Representation

A thorough problem representation should answer three questions:

Who is the patient?

Provide patient demographics
and risk factors

What is the temporal pattern?

Provide illness length —
hyperacute / acute / subacute / chronic

Provide Illness tempo —
stable / progressive / resolving / intermittent / waxing / waning

What is the clinical syndrome?

Provide key signs and symptoms

The problem representation activates illness scripts, mental representations of potential diagnoses, within the clinician’s memory. Through a comparison process, the clinician develops a prioritized differential diagnosis based on the degree of match between the patient’s problem representation and previous illness scripts (or disease prototypes).

Example

To illustrate the properties of effective problem representations, consider the following case:

A 60-year-old woman with rheumatoid arthritis presents with one day of left ankle pain and swelling as well one week of malaise. She has been on prednisone 20mg daily for the past 6 months. On exam, she is febrile and tachycardic, with left ankle edema, erythema, and tenderness with active and passive range of motion. Blood work is significant for a WBC of 15.

An effective problem representation succinctly answers the three key questions listed above: Who is the patient? What is the time course? What is the clinical syndrome?

A less succinct problem representation

A 60-year-old woman with rheumatoid arthritis presents with ankle pain and swelling in the setting of malaise, with exam significant for tachycardia, fever, left ankle arthritis, and leukocytosis.

A concise problem representation

A 60-year-old immunocompromised woman presents with acute monoarticular arthritis and the systemic inflammatory response syndrome (SIRS).

An effective problem representation includes discriminating features (1), and excludes nonspecific ones (e.g. malaise). It also translates the patient’s data into medical terms. For example, one day becomes acute; chronic daily use of 20mg of prednisone becomes immunocompromised; left ankle pain and swelling become monoarticular arthritis; and fever, tachycardia, and leukocytosis become SIRS. By comparing and contrasting opposing diagnostic features, these abstract semantic qualifiers (e.g. acute vs. chronic, dull vs. sharp, distal vs. proximal) add differentiating power to a problem representation (2-4).

Summary

By summarizing the most salient features and minimizing distractors, effective problem representations reduce cognitive load and facilitate problem-solving. Translating lay language into medical terminology enables easier access to the knowledge stored in the clinician’s illness scripts.